Mercurial > repos > blastem
diff blastem.c @ 149:139e5dcd6aa3
Make writes to control and data port block when DMA is in progress
| author | Mike Pavone <pavone@retrodev.com> |
|---|---|
| date | Tue, 01 Jan 2013 07:06:57 -0800 |
| parents | 177ba1a5af9c |
| children | 42c031184e8a |
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--- a/blastem.c Tue Jan 01 07:04:48 2013 -0800 +++ b/blastem.c Tue Jan 01 07:06:57 2013 -0800 @@ -115,11 +115,9 @@ sync_components(context); vdp_context * v_context = context->next_context; if (vdp_port < 0x10) { + int blocked; if (vdp_port < 4) { - vdp_data_port_write(v_context, value); - } else if(vdp_port < 8) { - int blocked = vdp_control_port_write(v_context, value); - if (blocked) { + while (vdp_data_port_write(v_context, value) < 0) { while(v_context->flags & FLAG_DMA_RUN) { vdp_run_dma_done(v_context, MCLKS_PER_FRAME); if (v_context->cycles >= MCLKS_PER_FRAME) { @@ -130,6 +128,27 @@ } } context->current_cycle = v_context->cycles / MCLKS_PER_68K; + } + } else if(vdp_port < 8) { + blocked = vdp_control_port_write(v_context, value); + if (blocked) { + while (blocked) { + while(v_context->flags & FLAG_DMA_RUN) { + vdp_run_dma_done(v_context, MCLKS_PER_FRAME); + if (v_context->cycles >= MCLKS_PER_FRAME) { + wait_render_frame(v_context); + vdp_adjust_cycles(v_context, MCLKS_PER_FRAME); + io_adjust_cycles(&gamepad_1, v_context->cycles/MCLKS_PER_68K, MCLKS_PER_FRAME/MCLKS_PER_68K); + io_adjust_cycles(&gamepad_2, v_context->cycles/MCLKS_PER_68K, MCLKS_PER_FRAME/MCLKS_PER_68K); + } + } + if (blocked < 0) { + blocked = vdp_control_port_write(v_context, value); + } else { + blocked = 0; + } + } + context->current_cycle = v_context->cycles / MCLKS_PER_68K; } else { if (v_context->regs[REG_MODE_2] & 0x20 && ((context->status & 0x7) < 6)) { if (context->int_cycle > VINT_CYCLE) {