Mercurial > repos > blastem
view z80_util.c @ 1767:8a29c250f352
More instruction timing fixes in old Z80 core
author | Michael Pavone <pavone@retrodev.com> |
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date | Mon, 25 Feb 2019 21:22:14 -0800 |
parents | 6e4faa10f9ee |
children | 72540af9c90a |
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#include <string.h> void z80_read_8(z80_context *context) { context->cycles += 3 * context->opts->gen.clock_divider; uint8_t *fast = context->fastread[context->scratch1 >> 10]; if (fast) { context->scratch1 = fast[context->scratch1 & 0x3FF]; } else { context->scratch1 = read_byte(context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context); } } void z80_write_8(z80_context *context) { context->cycles += 3 * context->opts->gen.clock_divider; uint8_t *fast = context->fastwrite[context->scratch2 >> 10]; if (fast) { fast[context->scratch2 & 0x3FF] = context->scratch1; } else { write_byte(context->scratch2, context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context); } } void z80_io_read8(z80_context *context) { uint32_t tmp_mask = context->opts->gen.address_mask; memmap_chunk const *tmp_map = context->opts->gen.memmap; uint32_t tmp_chunks = context->opts->gen.memmap_chunks; context->opts->gen.address_mask = context->io_mask; context->opts->gen.memmap = context->io_map; context->opts->gen.memmap_chunks = context->io_chunks; context->cycles += 4 * context->opts->gen.clock_divider; context->scratch1 = read_byte(context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context); context->opts->gen.address_mask = tmp_mask; context->opts->gen.memmap = tmp_map; context->opts->gen.memmap_chunks = tmp_chunks; } void z80_io_write8(z80_context *context) { uint32_t tmp_mask = context->opts->gen.address_mask; memmap_chunk const *tmp_map = context->opts->gen.memmap; uint32_t tmp_chunks = context->opts->gen.memmap_chunks; context->opts->gen.address_mask = context->io_mask; context->opts->gen.memmap = context->io_map; context->opts->gen.memmap_chunks = context->io_chunks; context->cycles += 4 * context->opts->gen.clock_divider; write_byte(context->scratch2, context->scratch1, (void **)context->mem_pointers, &context->opts->gen, context); context->opts->gen.address_mask = tmp_mask; context->opts->gen.memmap = tmp_map; context->opts->gen.memmap_chunks = tmp_chunks; } //quick hack until I get a chance to change which init method these get passed to static memmap_chunk const * tmp_io_chunks; static uint32_t tmp_num_io_chunks, tmp_io_mask; void init_z80_opts(z80_options * options, memmap_chunk const * chunks, uint32_t num_chunks, memmap_chunk const * io_chunks, uint32_t num_io_chunks, uint32_t clock_divider, uint32_t io_address_mask) { memset(options, 0, sizeof(*options)); options->gen.memmap = chunks; options->gen.memmap_chunks = num_chunks; options->gen.address_mask = 0xFFFF; options->gen.max_address = 0xFFFF; options->gen.clock_divider = clock_divider; tmp_io_chunks = io_chunks; tmp_num_io_chunks = num_io_chunks; tmp_io_mask = io_address_mask; } void z80_options_free(z80_options *opts) { free(opts); } z80_context * init_z80_context(z80_options *options) { z80_context *context = calloc(1, sizeof(z80_context)); context->opts = options; context->io_map = (memmap_chunk *)tmp_io_chunks; context->io_chunks = tmp_num_io_chunks; context->io_mask = tmp_io_mask; context->int_cycle = context->int_end_cycle = context->nmi_cycle = 0xFFFFFFFFU; z80_invalidate_code_range(context, 0, 0xFFFF); return context; } void z80_sync_cycle(z80_context *context, uint32_t target_cycle) { if (context->iff1 && context->int_cycle < target_cycle) { if (context->cycles > context->int_end_cycle) { context->int_cycle = 0xFFFFFFFFU; } else { target_cycle = context->int_cycle; } }; if (context->nmi_cycle < target_cycle) { target_cycle = context->nmi_cycle; } context->sync_cycle = target_cycle; } void z80_run(z80_context *context, uint32_t target_cycle) { if (context->reset || context->busack) { context->cycles = target_cycle; } else if (target_cycle > context->cycles) { if (context->busreq) { //busreq is sampled at the end of an m-cycle //we can approximate that by running for a single m-cycle after a bus request target_cycle = context->cycles + 4 * context->opts->gen.clock_divider; } z80_execute(context, target_cycle); if (context->busreq) { context->busack = 1; } } } void z80_assert_reset(z80_context * context, uint32_t cycle) { z80_run(context, cycle); context->reset = 1; } void z80_clear_reset(z80_context * context, uint32_t cycle) { z80_run(context, cycle); if (context->reset) { context->imode = 0; context->iff1 = context->iff2 = 0; context->pc = 0; context->reset = 0; if (context->busreq) { //TODO: Figure out appropriate delay context->busack = 1; } } } #define MAX_MCYCLE_LENGTH 6 void z80_assert_busreq(z80_context * context, uint32_t cycle) { z80_run(context, cycle); context->busreq = 1; //this is an imperfect aproximation since most M-cycles take less tstates than the max //and a short 3-tstate m-cycle can take an unbounded number due to wait states if (context->cycles - cycle > MAX_MCYCLE_LENGTH * context->opts->gen.clock_divider) { context->busack = 1; } } void z80_clear_busreq(z80_context * context, uint32_t cycle) { z80_run(context, cycle); context->busreq = 0; context->busack = 0; //there appears to be at least a 1 Z80 cycle delay between busreq //being released and resumption of execution context->cycles += context->opts->gen.clock_divider; } void z80_assert_nmi(z80_context *context, uint32_t cycle) { context->nmi_cycle = cycle; } uint8_t z80_get_busack(z80_context * context, uint32_t cycle) { z80_run(context, cycle); return context->busack; } void z80_invalidate_code_range(z80_context *context, uint32_t startA, uint32_t endA) { for(startA &= ~0x3FF; startA < endA; startA += 1024) { uint8_t *start = get_native_pointer(startA, (void**)context->mem_pointers, &context->opts->gen); if (start) { uint8_t *end = get_native_pointer(startA + 1023, (void**)context->mem_pointers, &context->opts->gen); if (!end || end - start != 1023) { start = NULL; } } context->fastread[startA >> 10] = start; start = get_native_write_pointer(startA, (void**)context->mem_pointers, &context->opts->gen); if (start) { uint8_t *end = get_native_write_pointer(startA + 1023, (void**)context->mem_pointers, &context->opts->gen); if (!end || end - start != 1023) { start = NULL; } } context->fastwrite[startA >> 10] = start; } } void z80_adjust_cycles(z80_context * context, uint32_t deduction) { context->cycles -= deduction; if (context->int_cycle != 0xFFFFFFFFU) { if (context->int_cycle > deduction) { context->int_cycle -= deduction; } else { context->int_cycle = 0; } } if (context->int_end_cycle != 0xFFFFFFFFU) { if (context->int_end_cycle > deduction) { context->int_end_cycle -= deduction; } else { context->int_end_cycle = 0; } } if (context->nmi_cycle != 0xFFFFFFFFU) { if (context->nmi_cycle > deduction) { context->nmi_cycle -= deduction; } else { context->nmi_cycle = 0; } } } void z80_serialize(z80_context *context, serialize_buffer *buf) { //TODO: Implement me } void z80_deserialize(deserialize_buffer *buf, void *vcontext) { //TODO: Implement me } void zinsert_breakpoint(z80_context * context, uint16_t address, uint8_t * bp_handler) { } void zremove_breakpoint(z80_context * context, uint16_t address) { }