repos/simple16: src/cpu.c annotate

annotate src/cpu.c @ 43:6e7bfe83d2b0

Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU

author	Michael Pavone <pavone@retrodev.com>
date	Sat, 27 Aug 2016 22:38:31 -0700
parents	5683d9ba9acc
children	51672bd41cdd

rev	line source
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	1 #include <stdint.h>
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	2 #include <stdlib.h>
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	3 #include <string.h>
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	4 #include <stdio.h>
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	5 #include "cpu.h"
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	6
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	7 enum {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	8 EXCEPTION_INTERRUPT_0,
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	9 EXCEPTION_INTERRUPT_1,
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	10 EXCEPTION_UNALIGNED_READ,
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	11 EXCEPTION_INVALID_INSTRUCTION
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	12 };
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	13
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	14 enum {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	15 STATE_NEED_FETCH,
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	16 STATE_NORMAL,
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	17 STATE_EXCEPTION_START
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	18 };
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	19
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	20 #define STATUS_INT0_ENABLE 1
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	21 #define STATUS_INT1_ENABLE 2
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	22 #define FLAG_Z 4
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	23 #define FLAG_C 8
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	24 #define FLAG_N 16
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	25
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	26 cpu* alloc_cpu(uint32_t clock_divider, uint32_t num_regions, memory_region *regions)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	27 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	28 size_t alloc_size = sizeof(cpu) + sizeof(memory_region) * num_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	29 cpu *context = malloc(alloc_size);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	30 memset(context, 0, alloc_size);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	31 context->clock_inc = clock_divider;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	32 context->num_mem_regions = num_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	33 memcpy(context->mem_regions, regions, num_regions*sizeof(memory_region));
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	34
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	35 return context;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	36 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	37
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	38 uint16_t cpu_read_16(cpu *context, uint32_t address)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	39 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	40 context->cycles += context->clock_inc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	41 if (address & 1) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	42 context->exception = EXCEPTION_UNALIGNED_READ;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	43 context->state = STATE_EXCEPTION_START;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	44 return 0xFFFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	45 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	46 memory_region *cur = context->mem_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	47 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	48 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	49 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_READ)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	50 return cur->base[address - cur->start] << 8 \| cur->base[address - cur->start + 1];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	51 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	52 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	53 return 0xFFFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	54 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	55
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	56 uint8_t cpu_read_8(cpu *context, uint32_t address)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	57 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	58 context->cycles += context->clock_inc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	59 memory_region *cur = context->mem_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	60 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	61 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	62 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_READ)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	63 return cur->base[address - cur->start];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	64 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	65 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	66 return 0xFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	67 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	68
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	69 void cpu_write_16(cpu *context, uint32_t address, uint16_t value)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	70 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	71 context->cycles += context->clock_inc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	72 if (address & 1) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	73 context->exception = EXCEPTION_UNALIGNED_READ;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	74 context->state = STATE_EXCEPTION_START;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	75 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	76 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	77 memory_region *cur = context->mem_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	78 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	79 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	80 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_WRITE)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	81 cur->base[address - cur->start] = value >> 8;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	82 cur->base[address - cur->start + 1] = value;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	83 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	84 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	85 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	86 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	87
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	88 void cpu_write_8(cpu *context, uint32_t address, uint8_t value)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	89 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	90 context->cycles += context->clock_inc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	91 memory_region *cur = context->mem_regions;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	92 for (memory_region *end = cur + context->num_mem_regions; cur < end; cur++)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	93 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	94 if (address >= cur->start && address <= cur->end && (cur->flags & MEM_WRITE)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	95 cur->base[address - cur->start] = value;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	96 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	97 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	98 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	99 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	100
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	101 uint16_t cpu_read_port(cpu *context, uint8_t port)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	102 {
20 a9364f5ee81a Fix timing of port IO Michael Pavone <pavone@retrodev.com> parents: 13 diff changeset	103 context->cycles += context->clock_inc;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	104 port &= 0xF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	105 if (context->port_handlers[port].read) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	106 return context->port_handlers[port].read(context, port);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	107 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	108 return 0xFFFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	109 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	110
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	111 void cpu_write_port(cpu *context, uint8_t port, uint16_t value)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	112 {
20 a9364f5ee81a Fix timing of port IO Michael Pavone <pavone@retrodev.com> parents: 13 diff changeset	113 context->cycles += context->clock_inc;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	114 port &= 0xF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	115 if (context->port_handlers[port].write) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	116 context->port_handlers[port].write(context, port, value);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	117 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	118 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	119
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	120 void fetch_instruction(cpu *context)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	121 {
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	122 context->prefetch = cpu_read_16(context, context->pc_msb \| context->regs[REG_PC]);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	123 context->regs[REG_PC] += 2;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	124 context->state = STATE_NORMAL;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	125 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	126
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	127 void vector_fetch(cpu *context)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	128 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	129 context->exception_pc = context->regs[REG_PC] - 2;
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	130 context->exception_pch = context->pc_msb >> 16;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	131 context->exception_sr = context->regs[REG_SR];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	132 context->regs[REG_SR] &= ~(STATUS_INT0_ENABLE \| STATUS_INT1_ENABLE);
26 083347ccd508 Implemented vblank interrupts and fixed a bug in exception vector address calculation Michael Pavone <pavone@retrodev.com> parents: 25 diff changeset	133 context->regs[REG_PC] = cpu_read_16(context, context->vector_base + context->exception * 2);
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	134 context->pc_msb = 0;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	135 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	136 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	137
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	138 uint16_t sign_extend(uint16_t val)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	139 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	140 if (val & 0x80) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	141 return val \| 0xFF00;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	142 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	143 return val;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	144 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	145
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	146 void update_flags_arith(cpu *context, uint32_t result)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	147 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	148 context->regs[REG_SR] &= ~(FLAG_N\|FLAG_C\|FLAG_Z);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	149 if (!(result & 0xFFFF)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	150 context->regs[REG_SR] \|= FLAG_Z;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	151 }
13 d8ae30286d17 Fix flag calculation and condition code tests Michael Pavone <pavone@retrodev.com> parents: 6 diff changeset	152 if (result & 0x8000) {
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	153 context->regs[REG_SR] \|= FLAG_N;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	154 }
13 d8ae30286d17 Fix flag calculation and condition code tests Michael Pavone <pavone@retrodev.com> parents: 6 diff changeset	155 if (result & 0x10000) {
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	156 context->regs[REG_SR] \|= FLAG_C;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	157 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	158 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	159
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	160 void update_flags_bitwise(cpu *context, uint32_t result)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	161 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	162 context->regs[REG_SR] &= ~(FLAG_N\|FLAG_Z);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	163 if (!(result & 0xFFFF)) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	164 context->regs[REG_SR] \|= FLAG_Z;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	165 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	166 if (result &= 0x8000) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	167 context->regs[REG_SR] \|= FLAG_N;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	168 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	169 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	170
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	171 void run_bcc(cpu *context, uint8_t condition, uint8_t a, uint8_t b)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	172 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	173
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	174 uint8_t doit = 0;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	175 switch (condition)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	176 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	177 case COND_ALWAYS:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	178 doit = 1;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	179 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	180 case COND_NEVER:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	181 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	182 case COND_ZERO:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	183 doit = context->regs[REG_SR] & FLAG_Z;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	184 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	185 case COND_NZERO:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	186 doit = !(context->regs[REG_SR] & FLAG_Z);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	187 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	188 case COND_NEG:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	189 doit = context->regs[REG_SR] & FLAG_N;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	190 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	191 case COND_POS:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	192 doit = !(context->regs[REG_SR] & FLAG_N);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	193 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	194 case COND_CARRY:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	195 doit = context->regs[REG_SR] & FLAG_C;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	196 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	197 case COND_NCARRY:
13 d8ae30286d17 Fix flag calculation and condition code tests Michael Pavone <pavone@retrodev.com> parents: 6 diff changeset	198 doit = !(context->regs[REG_SR] & FLAG_C);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	199 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	200 case COND_GREATER:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	201 //not zero and not carry
13 d8ae30286d17 Fix flag calculation and condition code tests Michael Pavone <pavone@retrodev.com> parents: 6 diff changeset	202 doit = !(context->regs[REG_SR] & FLAG_Z) && !(context->regs[REG_SR] & FLAG_C);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	203 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	204 case COND_LEQ:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	205 //zero or carry
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	206 doit = (context->regs[REG_SR] & FLAG_Z) \|\| (context->regs[REG_SR] & FLAG_C);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	207 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	208 default:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	209 context->exception = EXCEPTION_INVALID_INSTRUCTION;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	210 context->state = STATE_EXCEPTION_START;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	211 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	212 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	213
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	214 if (doit) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	215 context->regs[REG_PC] += sign_extend(a << 4 \| b) * 2;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	216 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	217 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	218 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	219
2 6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	220 uint16_t format_immediate(uint16_t val)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	221 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	222 if (val & 8) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	223 val \|= 0xFFF0;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	224 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	225 if (!val) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	226 val = 8;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	227 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	228 return val;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	229 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	230
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	231 void run_single_reg(cpu *context, uint8_t dst, uint8_t op)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	232 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	233 switch(op)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	234 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	235 case RETI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	236 context->regs[dst] = context->exception_ur;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	237 context->regs[REG_PC] = context->exception_pc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	238 context->regs[REG_SR] = context->exception_sr;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	239 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	240 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	241 case TRAPI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	242 context->state = STATE_EXCEPTION_START;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	243 context->exception = dst;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	244 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	245 case GETEPC:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	246 context->regs[dst] = context->exception_pc;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	247 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	248 case SETEPC:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	249 context->exception_pc = context->regs[dst];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	250 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	251 case GETESR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	252 context->regs[dst] = context->exception_sr;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	253 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	254 case SETESR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	255 context->exception_sr = context->regs[dst];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	256 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	257 case GETEUR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	258 context->regs[dst] = context->exception_ur;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	259 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	260 case SETEUR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	261 context->exception_ur = context->regs[dst];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	262 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	263 case GETENUM:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	264 context->regs[dst] = context->exception;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	265 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	266 case SETENUM:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	267 context->exception = context->regs[dst];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	268 break;
25 fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	269 case GETVBR:
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	270 context->regs[dst] = context->vector_base;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	271 break;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	272 case SETVBR:
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	273 context->vector_base = context->regs[dst];
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	274 break;
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	275 case GETDATABANKS:
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	276 context->regs[dst] = context->data_high_msb >> 7 \| context->data_low_msb >> 15;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	277 break;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	278 case SETDATABANKS:
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	279 context->data_high_msb = (context->regs[dst] & 0xFF00) << 7;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	280 context->data_low_msb = (context->regs[dst] & 0xFF) << 15;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	281 break;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	282 default:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	283 context->state = STATE_EXCEPTION_START;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	284 context->exception = EXCEPTION_INVALID_INSTRUCTION;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	285 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	286 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	287 if (dst == REG_PC) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	288 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	289 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	290 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	291
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	292 void run_single_source(cpu *context, uint8_t dst, uint8_t a, uint8_t op)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	293 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	294 uint32_t tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	295 uint8_t shift;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	296 switch(op)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	297 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	298 case MOVE:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	299 context->regs[dst] = context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	300 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	301 case NEG:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	302 tmp = -context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	303 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	304 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	305 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	306 case NOT:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	307 context->regs[dst] = ~context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	308 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	309 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	310 case CMP:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	311 tmp = context->regs[dst] - context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	312 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	313 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	314 case CALL:
36 5683d9ba9acc Fix call instruction for the case in which A reg == DST reg Michael Pavone <pavone@retrodev.com> parents: 26 diff changeset	315 tmp = context->regs[REG_PC] - 2;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	316 context->regs[REG_PC] = context->regs[a];
36 5683d9ba9acc Fix call instruction for the case in which A reg == DST reg Michael Pavone <pavone@retrodev.com> parents: 26 diff changeset	317 context->regs[dst] = tmp;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	318 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	319 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	320 case SWAP:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	321 tmp = context->regs[dst];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	322 context->regs[dst] = context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	323 context->regs[a] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	324 if (a == REG_PC) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	325 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	326 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	327 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	328 break;
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	329 case LONGJMP:
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	330 context->regs[REG_PC] = context->regs[a];
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	331 context->pc_msb = (context->regs[dst] & 0x7F) << 16;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	332 context->state = STATE_NEED_FETCH;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	333 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	334 case INI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	335 context->regs[dst] = cpu_read_port(context, a);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	336 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	337 case OUTI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	338 cpu_write_port(context, a, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	339 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	340 case ADDI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	341 tmp = context->regs[dst] + format_immediate(a);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	342 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	343 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	344 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	345 case ANDI:
2 6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	346 context->regs[dst] = context->regs[dst] & format_immediate(a);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	347 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	348 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	349 case ORI:
2 6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	350 context->regs[dst] = context->regs[dst] \| format_immediate(a);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	351 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	352 break;
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	353 case XORI:
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	354 context->regs[dst] = context->regs[dst] ^ format_immediate(a);
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	355 update_flags_bitwise(context, context->regs[dst]);
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	356 break;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	357 case LSI:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	358 shift = a & 7;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	359 if (!shift) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	360 shift = 8;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	361 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	362 if (a & 8) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	363 tmp = context->regs[dst] >> shift;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	364 tmp \|= (context->regs[dst] >> (shift - 1)) << 16 & 0x10000;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	365 } else {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	366 tmp = context->regs[dst] << (a & 7);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	367 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	368 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	369 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	370 break;
2 6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	371 case CMPI:
6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	372 tmp = a;
6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	373 if (a & 8) {
6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	374 a \|= 0xFFF0;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	375 }
2 6204c81e2933 Revert changes to handling of immediate versions of bitwise instructions. Replace asri with cmpi. Michael Pavone <pavone@retrodev.com> parents: 0 diff changeset	376 tmp = context->regs[dst] - a;
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	377 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	378 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	379 case SINGLE_REG:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	380 run_single_reg(context, dst, a);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	381 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	382 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	383 if (dst == REG_PC) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	384 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	385 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	386 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	387
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	388 uint32_t get_data_address(cpu *context, uint8_t a, uint8_t b)
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	389 {
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	390 uint32_t address = context->regs[a] + context->regs[b];
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	391 if (a == REG_PC \|\| b == REG_PC) {
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	392 address \|= context->pc_msb;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	393 } else if (address & 0x8000) {
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	394 address = (address & 0x7FFF) \| context->data_high_msb;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	395 } else {
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	396 address \|= context->data_low_msb;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	397 }
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	398 return address;
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	399 }
6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	400
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	401 void run_instruction(cpu *context)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	402 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	403 uint16_t instruction = context->prefetch;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	404 fetch_instruction(context);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	405 uint8_t dst = instruction >> 12;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	406 uint8_t a = instruction >> 8 & 0xF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	407 uint8_t b = instruction >> 4 & 0xF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	408 uint8_t op = instruction & 0xF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	409 uint32_t tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	410 switch (op)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	411 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	412 case LDIM:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	413 context->regs[dst] = sign_extend(a << 4 \| b);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	414 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	415 case LDIMH:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	416 context->regs[dst] &= 0xFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	417 context->regs[dst] \|= a << 12 \| b << 8;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	418 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	419 case LD8:
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	420 context->regs[dst] = cpu_read_8(context, get_data_address(context, a, b));
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	421 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	422 case LD16:
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	423 context->regs[dst] = cpu_read_16(context, get_data_address(context, a, b));
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	424 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	425 case STR8:
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	426 cpu_write_8(context, get_data_address(context, a, b), context->regs[dst]);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	427 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	428 case STR16:
43 6e7bfe83d2b0 Changed the design to vastly simplify the video hardware and support a 23-bit address space on the CPU Michael Pavone <pavone@retrodev.com> parents: 36 diff changeset	429 cpu_write_16(context,get_data_address(context, a, b), context->regs[dst]);
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	430 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	431 case ADD:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	432 tmp = context->regs[a] + context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	433 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	434 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	435 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	436 case ADC:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	437 tmp = context->regs[a] + context->regs[b] + (context->regs[REG_SR] & FLAG_C ? 1 : 0);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	438 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	439 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	440 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	441 case AND:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	442 context->regs[dst] = context->regs[a] & context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	443 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	444 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	445 case OR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	446 context->regs[dst] = context->regs[a] \| context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	447 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	448 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	449 case XOR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	450 context->regs[dst] = context->regs[a] ^ context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	451 update_flags_bitwise(context, context->regs[dst]);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	452 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	453 case LSL:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	454 tmp = context->regs[a] << context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	455 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	456 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	457 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	458 case LSR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	459 tmp = context->regs[a] >> context->regs[b];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	460 tmp \|= (context->regs[a] >> (context->regs[b] - 1)) << 16 & 0x10000;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	461 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	462 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	463 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	464 case ASR:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	465 tmp = context->regs[a];
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	466 if (tmp & 0x8000) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	467 tmp \|= 0xFFFF0000;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	468 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	469 tmp = tmp >> context->regs[b] & 0xFFFF;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	470 tmp \|= (context->regs[a] >> (context->regs[b] - 1)) << 16 & 0x10000;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	471 context->regs[dst] = tmp;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	472 update_flags_arith(context, tmp);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	473 break;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	474 case BCC:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	475 run_bcc(context, dst, a, b);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	476 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	477 case SINGLE_SOURCE:
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	478 run_single_source(context, dst, a, b);
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	479 return;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	480 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	481 if (dst == REG_PC) {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	482 context->state = STATE_NEED_FETCH;
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	483 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	484 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	485
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	486 void run_cpu(cpu *context, uint32_t target_cycle)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	487 {
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	488 while (context->cycles < target_cycle)
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	489 {
25 fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	490 context->current_target = target_cycle;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	491 context->pending_interrupts = get_current_interrupts(context);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	492 uint32_t int_cycle = next_interrupt_cycle(context, (~context->pending_interrupts) & 0x3);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	493 if (int_cycle < context->current_target) {
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	494 context->current_target = int_cycle;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	495 }
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	496 while (context->cycles < context->current_target)
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	497 {
25 fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	498 switch (context->state)
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	499 {
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	500 case STATE_NEED_FETCH:
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	501 fetch_instruction(context);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	502 break;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	503 case STATE_NORMAL:
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	504 if (context->regs[REG_SR] & context->pending_interrupts) {
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	505 context->state = STATE_EXCEPTION_START;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	506 context->exception = context->pending_interrupts & 1 ? EXCEPTION_INTERRUPT_0 : EXCEPTION_INTERRUPT_1;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	507 context->pending_interrupts &= ~(1 << context->exception);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	508 ack_interrupt(context, context->exception);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	509 } else {
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	510 run_instruction(context);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	511 }
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	512 break;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	513 case STATE_EXCEPTION_START:
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	514 vector_fetch(context);
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	515 break;
fb14515266f4 Implemented timer and timer interrupts. Added get/setvbr instructions. Fixed assembler bug. Moved mnemonics into a separate source file Michael Pavone <pavone@retrodev.com> parents: 20 diff changeset	516 }
0 7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	517 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	518 }
7e44f7d5810b Initial commit. CPU working well enough for simple hello world program. Michael Pavone <pavone@retrodev.com> parents: diff changeset	519 }

Mercurial > repos > simple16

annotate src/cpu.c @ 43:6e7bfe83d2b0