Mercurial > repos > blastem
diff blastem.c @ 668:5439ae7946ca
Made the Z80 core more contained by refactoring some code in blastem.c into z80_to_x86.c
author | Michael Pavone <pavone@retrodev.com> |
---|---|
date | Sat, 03 Jan 2015 18:23:04 -0800 |
parents | 30ccf56842d6 |
children | 7a9a7c96cb22 |
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line diff
--- a/blastem.c Sat Jan 03 16:08:23 2015 -0800 +++ b/blastem.c Sat Jan 03 18:23:04 2015 -0800 @@ -155,12 +155,6 @@ int break_on_sync = 0; int save_state = 0; -uint8_t reset = 1; -uint8_t need_reset = 0; -uint8_t busreq = 0; -uint8_t busack = 0; -uint32_t busack_cycle = CYCLE_NEVER; -uint8_t new_busack = 0; //#define DO_DEBUG_PRINT #ifdef DO_DEBUG_PRINT #define dprintf printf @@ -172,34 +166,18 @@ #define Z80_VINT_DURATION 128 +void z80_next_int_pulse(z80_context * z_context) +{ + genesis_context * gen = z_context->system; + z_context->int_pulse_start = vdp_next_vint_z80(gen->vdp); + z_context->int_pulse_end = z_context->int_pulse_start + Z80_VINT_DURATION; +} + void sync_z80(z80_context * z_context, uint32_t mclks) { #ifndef NO_Z80 - if (z80_enabled && !reset && !busreq) { - genesis_context * gen = z_context->system; - z_context->sync_cycle = mclks; - if (z_context->current_cycle < z_context->sync_cycle) { - if (need_reset) { - z80_reset(z_context); - need_reset = 0; - } - - while (z_context->current_cycle < z_context->sync_cycle) { - if (z_context->int_pulse_end < z_context->current_cycle || z_context->int_pulse_end == CYCLE_NEVER) { - z_context->int_pulse_start = vdp_next_vint_z80(gen->vdp); - z_context->int_pulse_end = z_context->int_pulse_start + Z80_VINT_DURATION; - } - if (z_context->iff1) { - z_context->int_cycle = z_context->int_pulse_start < z_context->int_enable_cycle ? z_context->int_enable_cycle : z_context->int_pulse_start; - } else { - z_context->int_cycle = CYCLE_NEVER; - } - z_context->target_cycle = z_context->sync_cycle < z_context->int_cycle ? z_context->sync_cycle : z_context->int_cycle; - dprintf("Running Z80 from cycle %d to cycle %d. Int cycle: %d\n", z_context->current_cycle, z_context->sync_cycle, z_context->int_cycle); - z_context->run(z_context); - dprintf("Z80 ran to cycle %d\n", z_context->current_cycle); - } - } + if (z80_enabled) { + z80_run(z_context, mclks); } else #endif { @@ -256,45 +234,8 @@ io_adjust_cycles(gen->ports, context->current_cycle, mclk_target); io_adjust_cycles(gen->ports+1, context->current_cycle, mclk_target); io_adjust_cycles(gen->ports+2, context->current_cycle, mclk_target); - if (busack_cycle != CYCLE_NEVER) { - if (busack_cycle > mclk_target) { - busack_cycle -= mclk_target; - } else { - busack_cycle = CYCLE_NEVER; - busack = new_busack; - } - } context->current_cycle -= mclk_target; - if (z_context->current_cycle >= mclk_target) { - z_context->current_cycle -= mclk_target; - } else { - z_context->current_cycle = 0; - } - if (z_context->int_cycle != CYCLE_NEVER) { - if (z_context->int_cycle >= mclk_target) { - z_context->int_cycle -= mclk_target; - } else { - z_context->int_cycle = 0; - } - } - if (z_context->int_pulse_start != CYCLE_NEVER) { - if (z_context->int_pulse_end >= mclk_target) { - z_context->int_pulse_end -= mclk_target; - if (z_context->int_pulse_start >= mclk_target) { - z_context->int_pulse_start -= mclk_target; - } else { - z_context->int_pulse_start = 0; - } - } - } else { - z_context->int_pulse_start = CYCLE_NEVER; - z_context->int_pulse_end = CYCLE_NEVER; - } - if (z_context->int_enable_cycle >= mclk_target) { - z_context->int_enable_cycle -= mclk_target; - } else { - z_context->int_enable_cycle = 0; - } + z80_adjust_cycles(z_context, mclk_target); if (mclks) { vdp_run_context(v_context, mclks); } @@ -458,7 +399,7 @@ value = vdp_hv_counter_read(v_context); //printf("HV Counter: %X at cycle %d\n", value, v_context->cycles); } - } else if (vdp_port < 0x18){ + } else if (vdp_port < 0x18) { printf("Illegal read from PSG port %X\n", vdp_port); exit(1); } else { @@ -520,11 +461,7 @@ { genesis_context * gen = context->system; if (location < 0x10000) { - if (busack_cycle <= context->current_cycle) { - busack = new_busack; - busack_cycle = CYCLE_NEVER; - } - if (!(busack || reset)) { + if (!z80_enabled || z80_get_busack(gen->z80, context->current_cycle)) { location &= 0x7FFF; if (location < 0x4000) { z80_ram[location & 0x1FFF] = value; @@ -578,54 +515,40 @@ } } else { if (location == 0x1100) { - if (busack_cycle <= context->current_cycle) { - busack = new_busack; - busack_cycle = CYCLE_NEVER; - } if (value & 1) { dputs("bus requesting Z80"); - - if(!reset && !busreq) { - sync_z80(gen->z80, context->current_cycle + Z80_ACK_DELAY*MCLKS_PER_Z80); - busack_cycle = gen->z80->current_cycle;//context->current_cycle + Z80_ACK_DELAY; - new_busack = Z80_REQ_ACK; + if (z80_enabled) { + z80_assert_busreq(gen->z80, context->current_cycle); } - busreq = 1; } else { - sync_z80(gen->z80, context->current_cycle); - if (busreq) { + if (gen->z80->busreq) { dputs("releasing z80 bus"); - #ifdef DO_DEBUG_PRINT +#ifdef DO_DEBUG_PRINT char fname[20]; sprintf(fname, "zram-%d", zram_counter++); FILE * f = fopen(fname, "wb"); fwrite(z80_ram, 1, sizeof(z80_ram), f); fclose(f); - #endif - busack_cycle = gen->z80->current_cycle + Z80_BUSY_DELAY; - new_busack = Z80_REQ_BUSY; - busreq = 0; +#endif } - //busack_cycle = CYCLE_NEVER; - //busack = Z80_REQ_BUSY; - + if (z80_enabled) { + z80_clear_busreq(gen->z80, context->current_cycle); + } } } else if (location == 0x1200) { sync_z80(gen->z80, context->current_cycle); if (value & 1) { - if (reset && busreq) { - new_busack = 0; - busack_cycle = gen->z80->current_cycle + Z80_ACK_DELAY;//context->current_cycle + Z80_ACK_DELAY; + if (z80_enabled) { + z80_clear_reset(gen->z80, context->current_cycle); + } else { + gen->z80->reset = 0; } - //TODO: Deal with the scenario in which reset is not asserted long enough - if (reset) { - need_reset = 1; - //TODO: Add necessary delay between release of reset and start of execution - gen->z80->current_cycle = context->current_cycle + 16 * MCLKS_PER_Z80; + } else { + if (z80_enabled) { + z80_assert_reset(gen->z80, context->current_cycle); + } else { + gen->z80->reset = 1; } - reset = 0; - } else { - reset = 1; } } } @@ -653,11 +576,7 @@ uint8_t value; genesis_context *gen = context->system; if (location < 0x10000) { - if (busack_cycle <= context->current_cycle) { - busack = new_busack; - busack_cycle = CYCLE_NEVER; - } - if (!(busack==Z80_REQ_BUSY || reset)) { + if (!z80_enabled || z80_get_busack(gen->z80, context->current_cycle)) { location &= 0x7FFF; if (location < 0x4000) { value = z80_ram[location & 0x1FFF]; @@ -702,14 +621,10 @@ } } else { if (location == 0x1100) { - if (busack_cycle <= context->current_cycle) { - busack = new_busack; - busack_cycle = CYCLE_NEVER; - } - value = Z80_RES_BUSACK || busack; - dprintf("Byte read of BUSREQ returned %d @ %d (reset: %d, busack: %d, busack_cycle %d)\n", value, context->current_cycle, reset, busack, busack_cycle); + value = z80_enabled ? !z80_get_busack(gen->z80, context->current_cycle) : 0; + dprintf("Byte read of BUSREQ returned %d @ %d (reset: %d)\n", value, context->current_cycle, gen->z80->reset); } else if (location == 0x1200) { - value = !reset; + value = !gen->z80->reset; } else { value = 0xFF; printf("Byte read of unknown IO location: %X\n", location); @@ -1105,9 +1020,6 @@ insert_breakpoint(&context, pc, debugger); } adjust_int_cycle(gen->m68k, gen->vdp); -#ifndef NO_Z80 - gen->z80->native_pc = z80_get_native_address_trans(gen->z80, gen->z80->pc); -#endif start_68k_context(&context, pc); } else { if (debugger) { @@ -1364,6 +1276,7 @@ z80_options z_opts; init_z80_opts(&z_opts, z80_map, 5, MCLKS_PER_Z80); init_z80_context(&z_context, &z_opts); + z80_assert_reset(&z_context, 0); #endif z_context.system = &gen;