Mercurial > repos > blastem

comparison vdp.c @ 1319:b6796d63977f

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix some edge cases with regards to 128KB VRAM mode and the SAT cache
author Michael Pavone <pavone@retrodev.com>
date Sun, 16 Apr 2017 18:43:34 -0700
parents bfdd450e7dea
children df3d690cb2c3
comparison
equal deleted inserted replaced
1318:bfdd450e7dea 1319:b6796d63977f
755 context->flags &= ~FLAG_DMA_RUN; 755 context->flags &= ~FLAG_DMA_RUN;
756 context->cd &= 0xF; 756 context->cd &= 0xF;
757 } 757 }
758 } 758 }
759 759
760 void write_vram_word(vdp_context *context, uint32_t address, uint8_t value)
761 {
762 if (!(address & 4)) {
763 uint32_t sat_address = (context->regs[REG_SAT] & 0xFF) << 9;
764 if(address >= sat_address && address < (sat_address + SAT_CACHE_SIZE*2)) {
765 uint16_t cache_address = address - sat_address;
766 cache_address = (cache_address & 3) | (cache_address >> 1 & 0x1FC);
767 context->sat_cache[cache_address] = value >> 8;
768 context->sat_cache[cache_address^1] = value;
769 }
770 }
771 address = (address & 0x3FC) | (address >> 1 & 0xFC01) | (address >> 9 & 0x2);
772 address ^= 1;
773 //TODO: Support an option to actually have 128KB of VRAM
774 context->vdpmem[address] = value;
775 }
776
760 void write_vram_byte(vdp_context *context, uint32_t address, uint8_t value) 777 void write_vram_byte(vdp_context *context, uint32_t address, uint8_t value)
761 { 778 {
762 if (context->regs[REG_MODE_2] & BIT_MODE_5) { 779 if (context->regs[REG_MODE_2] & BIT_MODE_5) {
763 if (context->regs[REG_MODE_2] & BIT_128K_VRAM) {
764 address = (address & 0x3FC) | (address >> 1 & 0xFC01) | (address >> 9 & 0x2);
765 address ^= 1;
766 } else {
767 address &= 0xFFFF;
768 }
769 if (!(address & 4)) { 780 if (!(address & 4)) {
770 uint16_t sat_address = (context->regs[REG_SAT] & 0x7F) << 9; 781 uint32_t sat_address = (context->regs[REG_SAT] & 0x7F) << 9;
771 if(address >= sat_address && address < (sat_address + SAT_CACHE_SIZE*2)) { 782 if(address >= sat_address && address < (sat_address + SAT_CACHE_SIZE*2)) {
772 uint16_t cache_address = address - sat_address; 783 uint16_t cache_address = address - sat_address;
773 cache_address = (cache_address & 3) | (cache_address >> 1 & 0x1FC); 784 cache_address = (cache_address & 3) | (cache_address >> 1 & 0x1FC);
774 context->sat_cache[cache_address] = value; 785 context->sat_cache[cache_address] = value;
775 } 786 }
776 } 787 }
788 address &= 0xFFFF;
777 } else { 789 } else {
778 address = mode4_address_map[address & 0x3FFF]; 790 address = mode4_address_map[address & 0x3FFF];
779 } 791 }
780 context->vdpmem[address] = value; 792 context->vdpmem[address] = value;
781 } 793 }
794 if (context->fifo_read >= 0 && start->cycle <= context->cycles) { 806 if (context->fifo_read >= 0 && start->cycle <= context->cycles) {
795 switch (start->cd & 0xF) 807 switch (start->cd & 0xF)
796 { 808 {
797 case VRAM_WRITE: 809 case VRAM_WRITE:
798 //TODO: Support actually having 128K VRAM as an option 810 //TODO: Support actually having 128K VRAM as an option
799 if (start->partial || (context->regs[REG_MODE_2] & BIT_128K_VRAM)) { 811 if ((context->regs[REG_MODE_2] & (BIT_128K_VRAM|BIT_MODE_5)) == (BIT_128K_VRAM|BIT_MODE_5)) {
812 write_vram_word(context, start->address, start->value);
813 } else if (start->partial) {
800 //printf("VRAM Write: %X to %X at %d (line %d, slot %d)\n", start->value, start->address ^ 1, context->cycles, context->cycles/MCLKS_LINE, (context->cycles%MCLKS_LINE)/16); 814 //printf("VRAM Write: %X to %X at %d (line %d, slot %d)\n", start->value, start->address ^ 1, context->cycles, context->cycles/MCLKS_LINE, (context->cycles%MCLKS_LINE)/16);
801 write_vram_byte(context, start->address ^ 1, start->partial == 2 ? start->value >> 8 : start->value); 815 write_vram_byte(context, start->address ^ 1, start->partial == 2 ? start->value >> 8 : start->value);
802 } else { 816 } else {
803 //printf("VRAM Write High: %X to %X at %d (line %d, slot %d)\n", start->value >> 8, start->address, context->cycles, context->cycles/MCLKS_LINE, (context->cycles%MCLKS_LINE)/16); 817 //printf("VRAM Write High: %X to %X at %d (line %d, slot %d)\n", start->value >> 8, start->address, context->cycles, context->cycles/MCLKS_LINE, (context->cycles%MCLKS_LINE)/16);
804 write_vram_byte(context, start->address, start->value >> 8); 818 write_vram_byte(context, start->address, start->value >> 8);