Mercurial > repos > blastem
changeset 889:2d1122123fe9
Approximation of refresh wait states
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Mon, 16 Nov 2015 21:57:17 -0800 |
| parents | bc127fa1f800 |
| children | 12b1a8a32306 |
| files | blastem.c |
| diffstat | 1 files changed, 12 insertions(+), 2 deletions(-) [+] |
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--- a/blastem.c Sat Nov 14 22:06:24 2015 -0800 +++ b/blastem.c Mon Nov 16 21:57:17 2015 -0800 @@ -230,12 +230,21 @@ //printf("Target: %d, YM bufferpos: %d, PSG bufferpos: %d\n", target, gen->ym->buffer_pos, gen->psg->buffer_pos * 2); } +#define REFRESH_INTERVAL 130 +#define REFRESH_DELAY 2 uint32_t last_frame_num; +uint32_t last_sync_cycle; +uint32_t refresh_counter; m68k_context * sync_components(m68k_context * context, uint32_t address) { genesis_context * gen = context->system; vdp_context * v_context = gen->vdp; z80_context * z_context = gen->z80; + //lame estimation of refresh cycle delay + refresh_counter += context->current_cycle - last_sync_cycle; + context->current_cycle += REFRESH_DELAY * MCLKS_PER_68K * (refresh_counter / (MCLKS_PER_68K * REFRESH_INTERVAL)); + refresh_counter = refresh_counter % (MCLKS_PER_68K * REFRESH_INTERVAL); + uint32_t mclks = context->current_cycle; sync_z80(z_context, mclks); sync_sound(gen, mclks); @@ -295,6 +304,7 @@ context->sync_cycle = context->current_cycle + 1; } } + last_sync_cycle = context->current_cycle; return context; } @@ -354,7 +364,7 @@ } if (v_context->cycles != before_cycle) { //printf("68K paused for %d (%d) cycles at cycle %d (%d) for write\n", v_context->cycles - context->current_cycle, v_context->cycles - before_cycle, context->current_cycle, before_cycle); - context->current_cycle = v_context->cycles; + last_sync_cycle = context->current_cycle = v_context->cycles; //Lock the Z80 out of the bus until the VDP access is complete gen->bus_busy = 1; sync_z80(gen->z80, v_context->cycles); @@ -427,7 +437,7 @@ } if (v_context->cycles != before_cycle) { //printf("68K paused for %d (%d) cycles at cycle %d (%d) for read\n", v_context->cycles - context->current_cycle, v_context->cycles - before_cycle, context->current_cycle, before_cycle); - context->current_cycle = v_context->cycles; + last_sync_cycle = context->current_cycle = v_context->cycles; //Lock the Z80 out of the bus until the VDP access is complete genesis_context *gen = context->system; gen->bus_busy = 1;