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Add the 3 cycle delay back in to Z80 bank area access
author Michael Pavone <pavone@retrodev.com>
date Thu, 01 Jan 2015 22:18:32 -0800
parents 759c38bf97f8
children 01c51f397db2
comparison
equal deleted inserted replaced
659:759c38bf97f8 660:e7cae6d9aaa6
417 417
418 void * z80_vdp_port_write(uint32_t vdp_port, void * vcontext, uint8_t value) 418 void * z80_vdp_port_write(uint32_t vdp_port, void * vcontext, uint8_t value)
419 { 419 {
420 z80_context * context = vcontext; 420 z80_context * context = vcontext;
421 genesis_context * gen = context->system; 421 genesis_context * gen = context->system;
422 vdp_port &= 0xFF;
422 if (vdp_port & 0xE0) { 423 if (vdp_port & 0xE0) {
423 printf("machine freeze due to write to Z80 address %X\n", 0x7F00 | vdp_port); 424 printf("machine freeze due to write to Z80 address %X\n", 0x7F00 | vdp_port);
424 exit(1); 425 exit(1);
425 } 426 }
426 if (vdp_port < 0x10) { 427 if (vdp_port < 0x10) {
759 } 760 }
760 761
761 uint8_t z80_read_bank(uint32_t location, void * vcontext) 762 uint8_t z80_read_bank(uint32_t location, void * vcontext)
762 { 763 {
763 z80_context * context = vcontext; 764 z80_context * context = vcontext;
765 //typical delay from bus arbitration
766 context->current_cycle += 3;
767
768 location &= 0x7FFF;
769 //TODO: add cycle for an access right after a previous one
770 //TODO: block Z80 if VDP has the bus or the 68K is blocked on a VDP access
771 if (context->mem_pointers[1]) {
772 return context->mem_pointers[1][location ^ 1];
773 }
764 uint32_t address = context->bank_reg << 15 | location; 774 uint32_t address = context->bank_reg << 15 | location;
765 if (address >= 0xC00000 && address < 0xE00000) { 775 if (address >= 0xC00000 && address < 0xE00000) {
766 return z80_vdp_port_read(location & 0xFF, context); 776 return z80_vdp_port_read(location & 0xFF, context);
767 } else { 777 } else {
768 fprintf(stderr, "Unhandled read by Z80 from address %X through banked memory area\n", address); 778 fprintf(stderr, "Unhandled read by Z80 from address %X through banked memory area (%X)\n", address, context->bank_reg << 15);
769 } 779 }
770 return 0; 780 return 0;
771 } 781 }
772 782
773 void *z80_write_bank(uint32_t location, void * vcontext, uint8_t value) 783 void *z80_write_bank(uint32_t location, void * vcontext, uint8_t value)
774 { 784 {
775 z80_context * context = vcontext; 785 z80_context * context = vcontext;
786 //typical delay from bus arbitration
787 context->current_cycle += 3;
788 location &= 0x7FFF;
789 //TODO: add cycle for an access right after a previous one
790 //TODO: block Z80 if VDP has the bus or the 68K is blocked on a VDP access
776 uint32_t address = context->bank_reg << 15 | location; 791 uint32_t address = context->bank_reg << 15 | location;
777 if (address >= 0xE00000) { 792 if (address >= 0xE00000) {
778 address &= 0xFFFF; 793 address &= 0xFFFF;
779 ((uint8_t *)ram)[address ^ 1] = value; 794 ((uint8_t *)ram)[address ^ 1] = value;
780 } else if (address >= 0xC00000) { 795 } else if (address >= 0xC00000) {
789 { 804 {
790 z80_context * context = vcontext; 805 z80_context * context = vcontext;
791 806
792 context->bank_reg = (context->bank_reg >> 1 | value << 8) & 0x1FF; 807 context->bank_reg = (context->bank_reg >> 1 | value << 8) & 0x1FF;
793 if (context->bank_reg < 0x80) { 808 if (context->bank_reg < 0x80) {
794 context->mem_pointers[1] = context->mem_pointers[2] + (context->bank_reg << 15); 809 genesis_context *gen = context->system;
810 context->mem_pointers[1] = get_native_pointer(context->bank_reg << 15, (void **)gen->m68k->mem_pointers, &gen->m68k->options->gen);
795 } else { 811 } else {
796 context->mem_pointers[1] = NULL; 812 context->mem_pointers[1] = NULL;
797 } 813 }
798 814
799 return context; 815 return context;
1176 } 1192 }
1177 } 1193 }
1178 } 1194 }
1179 #ifndef NO_Z80 1195 #ifndef NO_Z80
1180 const memmap_chunk z80_map[] = { 1196 const memmap_chunk z80_map[] = {
1181 { 0x0000, 0x4000, 0x1FFF, 0, MMAP_READ | MMAP_WRITE | MMAP_CODE, z80_ram, NULL, NULL, NULL, NULL }, 1197 { 0x0000, 0x4000, 0x1FFF, 0, MMAP_READ | MMAP_WRITE | MMAP_CODE, z80_ram, NULL, NULL, NULL, NULL },
1182 { 0x8000, 0x10000, 0x7FFF, 1, MMAP_READ | MMAP_PTR_IDX | MMAP_FUNC_NULL | MMAP_BYTESWAP, NULL, NULL, NULL, z80_read_bank, z80_write_bank}, 1198 { 0x8000, 0x10000, 0x7FFF, 0, 0, NULL, NULL, NULL, z80_read_bank, z80_write_bank},
1183 { 0x4000, 0x6000, 0x0003, 0, 0, NULL, NULL, NULL, z80_read_ym, z80_write_ym}, 1199 { 0x4000, 0x6000, 0x0003, 0, 0, NULL, NULL, NULL, z80_read_ym, z80_write_ym},
1184 { 0x6000, 0x6100, 0xFFFF, 0, 0, NULL, NULL, NULL, NULL, z80_write_bank_reg}, 1200 { 0x6000, 0x6100, 0xFFFF, 0, 0, NULL, NULL, NULL, NULL, z80_write_bank_reg},
1185 { 0x7F00, 0x8000, 0x00FF, 0, 0, NULL, NULL, NULL, z80_vdp_port_read, z80_vdp_port_write} 1201 { 0x7F00, 0x8000, 0x00FF, 0, 0, NULL, NULL, NULL, z80_vdp_port_read, z80_vdp_port_write}
1186 }; 1202 };
1187 #endif 1203 #endif
1188 1204
1189 int main(int argc, char ** argv) 1205 int main(int argc, char ** argv)
1190 { 1206 {