Mercurial > repos > blastem

changeset 317:e5e8b48ad157

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Initial stab at horizontal interrupts and improving accuracy of vertical interrupts. Also added the VINT pending flag to status port.
author Mike Pavone <pavone@retrodev.com>
date Fri, 10 May 2013 22:57:56 -0700
parents fd7c24b97ebf
children 789f2f5f2277
files blastem.c m68k_to_x86.h runtime.S vdp.c vdp.h
diffstat 5 files changed, 127 insertions(+), 22 deletions(-) [+]
line wrap: on
line diff
--- a/blastem.c	Thu May 09 20:59:49 2013 -0700
+++ b/blastem.c	Fri May 10 22:57:56 2013 -0700
@@ -107,21 +107,39 @@
 	return 0;
 }
 
-#define VINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_68K)
-#define ZVINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_Z80)
+//TODO: Make these dependent on the video mode
+//#define VINT_CYCLE ((MCLKS_LINE * 225 + (148 + 40) * 4)/MCLKS_PER_68K)
+#define ZVINT_CYCLE ((MCLKS_LINE * 225 + (148 + 40) * 4)/MCLKS_PER_Z80)
+//#define VINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_68K)
+//#define ZVINT_CYCLE ((MCLKS_LINE * 226)/MCLKS_PER_Z80)
 
 void adjust_int_cycle(m68k_context * context, vdp_context * v_context)
 {
-	if (!(v_context->regs[REG_MODE_2] & 0x20 && ((context->status & 0x7) < 6)) || context->current_cycle >= VINT_CYCLE) {
-		context->int_cycle = CYCLE_NEVER;
-		context->target_cycle = context->sync_cycle;
-	} else if (context->int_cycle > VINT_CYCLE) {
-		context->int_cycle = VINT_CYCLE;
-		context->int_num = 6;
-		if (context->int_cycle < context->sync_cycle) {
-			context->target_cycle = context->int_cycle;
+	context->int_cycle = CYCLE_NEVER;
+	if ((context->status & 0x7) < 6) {
+		uint32_t next_vint = vdp_next_vint(v_context);
+		if (next_vint != CYCLE_NEVER) {
+			next_vint /= MCLKS_PER_68K;
+			context->int_cycle = next_vint;
+			context->int_num = 6;
+		}
+		if ((context->status & 0x7) < 4) {
+			uint32_t next_hint = vdp_next_hint(v_context);
+			if (next_hint != CYCLE_NEVER) {
+				next_hint /= MCLKS_PER_68K;
+				if (next_hint < context->int_cycle) {
+					context->int_cycle = next_hint;
+					context->int_num = 4;
+			
+				}
+			}
 		}
 	}
+
+	context->target_cycle = context->int_cycle < context->sync_cycle ? context->int_cycle : context->sync_cycle;
+	/*printf("Cyc: %d, Trgt: %d, Int Cyc: %d, Int: %d, Mask: %X, V: %d, H: %d, HICount: %d, HReg: %d, Line: %d\n", 
+		context->current_cycle, context->target_cycle, context->int_cycle, context->int_num, (context->status & 0x7), 
+		v_context->regs[REG_MODE_2] & 0x20, v_context->regs[REG_MODE_1] & 0x10, v_context->hint_counter, v_context->regs[REG_HINT], v_context->cycles / MCLKS_LINE);*/
 }
 
 int break_on_sync = 0;
@@ -196,6 +214,10 @@
 		//printf("running VDP for %d cycles\n", mclks - v_context->cycles);
 		vdp_run_context(v_context, mclks);
 	}
+	if (context->int_ack) {
+		vdp_int_ack(v_context, context->int_ack);
+		context->int_ack = 0;
+	}
 	adjust_int_cycle(context, v_context);
 	if (break_on_sync && address) {
 		break_on_sync = 0;
--- a/m68k_to_x86.h	Thu May 09 20:59:49 2013 -0700
+++ b/m68k_to_x86.h	Fri May 10 22:57:56 2013 -0700
@@ -28,7 +28,7 @@
 typedef struct {
 	uint8_t         flags[5];
 	uint8_t         status;
-	uint16_t        reserved;
+	uint16_t        int_ack;
 	uint32_t        dregs[8];
 	uint32_t        aregs[9];
 	uint32_t		target_cycle; //cycle at which the next synchronization or interrupt occurs
--- a/runtime.S	Thu May 09 20:59:49 2013 -0700
+++ b/runtime.S	Fri May 10 22:57:56 2013 -0700
@@ -42,6 +42,7 @@
 	or %cl, 5(%rsi)
 	/* calculate interrupt vector address */
 	mov 92(%rsi), %ecx
+	mov %cx, 6(%rsi) /* interrupt acknowlege */
 	shl $2, %ecx
 	add $0x60, %ecx
 	call m68k_read_long_scratch1
--- a/vdp.c	Thu May 09 20:59:49 2013 -0700
+++ b/vdp.c	Fri May 10 22:57:56 2013 -0700
@@ -1028,18 +1028,34 @@
 		if (!line) {
 			latch_mode(context);
 		}
+		uint32_t linecyc = context->cycles % MCLKS_LINE;
+		if (linecyc == 0) {
+			if (line <= 1 || line >= active_lines) {
+				context->hint_counter = context->regs[REG_HINT];
+			} else if (context->hint_counter) {
+				context->hint_counter--;
+			} else {
+				context->flags2 |= FLAG2_HINT_PENDING;
+				context->hint_counter = context->regs[REG_HINT];
+			}
+		} else if(line == active_lines) {
+			uint32_t intcyc = context->latched_mode & BIT_H40 ? (148 + 40) * 4 :  (132 + 28) * 5;;
+			if (linecyc == intcyc) {
+				context->flags2 |= FLAG2_VINT_PENDING;
+			}
+		}
 		if (line < active_lines && context->regs[REG_MODE_2] & DISPLAY_ENABLE) {
 			//first sort-of active line is treated as 255 internally
 			//it's used for gathering sprite info for line 
 			line = (line - 1) & 0xFF;
-			uint32_t linecyc = context->cycles % MCLKS_LINE;
 			
 			//Convert to slot number
 			if (context->latched_mode & BIT_H40){
 				//TODO: Deal with nasty clock switching during HBLANK
+				uint32_t clock_inc = MCLKS_LINE-linecyc < 16 ? MCLKS_LINE-linecyc : 16;
 				linecyc = linecyc/16;
 				vdp_h40(line, linecyc, context);
-				context->cycles += 16;
+				context->cycles += clock_inc;
 			} else {
 				linecyc = linecyc/20;
 				vdp_h32(line, linecyc, context);
@@ -1053,8 +1069,9 @@
 				check_render_bg(context, line);
 			}
 			if (context->latched_mode & BIT_H40){
+				uint32_t clock_inc = MCLKS_LINE-linecyc < 16 ? MCLKS_LINE-linecyc : 16;
 				//TODO: Deal with nasty clock switching during HBLANK
-				context->cycles += 16;
+				context->cycles += clock_inc;
 			} else {
 				context->cycles += 20;
 			}
@@ -1173,6 +1190,9 @@
 	if (context->fifo_cur == context->fifo_end) {
 		value |= 0x100;
 	}
+	if (context->flags2 & FLAG2_VINT_PENDING) {
+		value |- 0x80;
+	}
 	if (context->flags & FLAG_DMA_RUN) {
 		value |= 0x2;
 	}
@@ -1180,6 +1200,9 @@
 	if (line >= (context->latched_mode & BIT_PAL ? PAL_ACTIVE : NTSC_ACTIVE)) {
 		value |= 0x8;
 	}
+	if (context->latched_mode & BIT_PAL) {//Not sure about this, need to verify
+		value |= 0x1;
+	}
 	//TODO: Lots of other bits in status port
 	return value;
 }
@@ -1268,6 +1291,57 @@
 	}
 }
 
+uint32_t vdp_next_hint(vdp_context * context)
+{
+	if (!(context->regs[REG_MODE_1] & 0x10)) {
+		return 0xFFFFFFFF;
+	}
+	if (context->flags2 & FLAG2_HINT_PENDING) {
+		return context->cycles;
+	}
+	uint32_t active_lines = context->latched_mode & BIT_PAL ? PAL_ACTIVE : NTSC_ACTIVE;
+	uint32_t line = context->cycles / MCLKS_LINE;
+	if (line >= active_lines) {
+		return 0xFFFFFFFF;
+	}
+	uint32_t linecyc = context->cycles % MCLKS_LINE;
+	uint32_t hcycle = context->cycles + context->hint_counter * MCLKS_LINE + MCLKS_LINE - linecyc;
+	if (!line) {
+		hcycle += MCLKS_LINE;
+	}
+	return hcycle;
+}
+
+uint32_t vdp_next_vint(vdp_context * context)
+{
+	if (!(context->regs[REG_MODE_2] & 0x20)) {
+		return 0xFFFFFFFF;
+	}
+	if (context->flags2 & FLAG2_VINT_PENDING) {
+		return context->cycles;
+	}
+	uint32_t active_lines = context->latched_mode & BIT_PAL ? PAL_ACTIVE : NTSC_ACTIVE;
+	uint32_t vcycle =  MCLKS_LINE * active_lines;
+	if (context->latched_mode & BIT_H40) {
+		vcycle += (148 + 40) * 4;
+	} else {
+		vcycle += (132 + 28) * 5;
+	}
+	if (vcycle < context->cycles) {
+		return 0xFFFFFFFF;
+	}
+	return vcycle;
+}
+
+void vdp_int_ack(vdp_context * context, uint16_t int_num)
+{
+	if (int_num == 6) {
+		context->flags2 &= ~FLAG2_VINT_PENDING;
+	} else if(int_num ==4) {
+		context->flags2 &= ~FLAG2_HINT_PENDING;
+	}
+}
+
 #define GST_VDP_REGS 0xFA
 #define GST_VDP_MEM 0x12478
 
--- a/vdp.h	Thu May 09 20:59:49 2013 -0700
+++ b/vdp.h	Fri May 10 22:57:56 2013 -0700
@@ -30,14 +30,17 @@
 
 #define MCLKS_LINE 3420
 
-#define FLAG_DOT_OFLOW 0x1
-#define FLAG_CAN_MASK  0x2
-#define FLAG_MASKED    0x4
-#define FLAG_WINDOW    0x8
-#define FLAG_PENDING   0x10
-#define FLAG_UNUSED_SLOT 0x20
-#define FLAG_DMA_RUN   0x40
-#define FLAG_DMA_PROG  0x80
+#define FLAG_DOT_OFLOW     0x01
+#define FLAG_CAN_MASK      0x02
+#define FLAG_MASKED        0x04
+#define FLAG_WINDOW        0x08
+#define FLAG_PENDING       0x10
+#define FLAG_UNUSED_SLOT   0x20
+#define FLAG_DMA_RUN       0x40
+#define FLAG_DMA_PROG      0x80
+
+#define FLAG2_VINT_PENDING 0x01
+#define FLAG2_HINT_PENDING 0x02
 
 #define DISPLAY_ENABLE 0x40
 
@@ -115,6 +118,8 @@
 	uint16_t    dma_val;
 	uint8_t     v_offset;
 	uint8_t     dma_cd;
+	uint8_t     hint_counter;
+	uint8_t     flags2;
 	uint8_t     *tmp_buf_a;
 	uint8_t     *tmp_buf_b;
 } vdp_context;
@@ -133,5 +138,8 @@
 uint16_t vdp_data_port_read(vdp_context * context);
 uint16_t vdp_hv_counter_read(vdp_context * context);
 void vdp_adjust_cycles(vdp_context * context, uint32_t deduction);
+uint32_t vdp_next_hint(vdp_context * context);
+uint32_t vdp_next_vint(vdp_context * context);
+void vdp_int_ack(vdp_context * context, uint16_t int_num);
 
 #endif //VDP_H_