Mercurial > repos > blastem
diff cdd_mcu.c @ 2419:0871f555eff6
Fix some CD-ROM emulation issues and make timing better match my MCD2. Seems to fix or at least improve video playback in Iron Helix and Power Rangers
| author | Michael Pavone <pavone@retrodev.com> |
|---|---|
| date | Thu, 18 Jan 2024 23:03:58 -0800 |
| parents | c66e051de8a6 |
| children | bcfa5e272f5e |
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--- a/cdd_mcu.c Wed Jan 17 23:51:37 2024 -0800 +++ b/cdd_mcu.c Thu Jan 18 23:03:58 2024 -0800 @@ -11,7 +11,7 @@ #define NIBBLE_CLOCKS (CDD_MCU_DIVIDER * 77) #define BYTE_CLOCKS (SECTOR_CLOCKS/2352) // 96 #define SUBCODE_CLOCKS (SECTOR_CLOCKS/98) -#define PROCESSING_DELAY 54000 //approximate, based on Wondermega M1 measurements +#define PROCESSING_DELAY 121600 //approximate, based on relative level 4 and level 5 interrupt timing on MCD2 in pause_test //lead in start max diameter 46 mm //program area start max diameter 50 mm @@ -179,7 +179,6 @@ static void update_status(cdd_mcu *context, uint16_t *gate_array) { gate_array[GAO_CDD_CTRL] |= BIT_MUTE; - uint32_t prev_pba = context->head_pba; switch (context->status) { case DS_STOP: @@ -255,16 +254,16 @@ switch (force_not_ready ? SF_NOTREADY : context->requested_format) { case SF_ABSOLUTE: - if (context->toc_valid && prev_pba >= LEADIN_SECTORS) { - lba_to_status(context, prev_pba - LEADIN_SECTORS); + if (context->toc_valid && context->head_pba >= LEADIN_SECTORS) { + lba_to_status(context, context->head_pba - LEADIN_SECTORS); context->status_buffer.format = SF_ABSOLUTE; } else { context->status_buffer.format = SF_NOTREADY; } break; case SF_RELATIVE: - if (context->toc_valid && prev_pba >= LEADIN_SECTORS) { - uint32_t lba =prev_pba - LEADIN_SECTORS; + if (context->toc_valid && context->head_pba >= LEADIN_SECTORS) { + uint32_t lba =context->head_pba - LEADIN_SECTORS; for (uint32_t i = 0; i < context->media->num_tracks; i++) { if (lba < context->media->tracks[i].end_lba) { @@ -295,8 +294,8 @@ } break; case SF_TRACK: - if (context->toc_valid && prev_pba >= LEADIN_SECTORS) { - uint32_t lba =prev_pba - LEADIN_SECTORS; + if (context->toc_valid && context->head_pba >= LEADIN_SECTORS) { + uint32_t lba =context->head_pba - LEADIN_SECTORS; uint32_t i; for (i = 0; i < context->media->num_tracks; i++) { @@ -373,7 +372,7 @@ } lba_to_status(context, lba); if (context->media->tracks[context->requested_track - 1].type == TRACK_DATA) { - context->status_buffer.b.tocn.frame_low |= 0x80; + context->status_buffer.b.tocn.frame_high |= 0x8; } context->status_buffer.b.tocn.track_low = context->requested_track % 10; context->status_buffer.format = SF_TOCN; @@ -663,10 +662,7 @@ context->next_subcode_int_cycle = CYCLE_NEVER; } if (old_coarse != context->coarse_seek) { - context->next_int_cycle = cd_block_to_mclks(context->cycle + PROCESSING_DELAY + 7 * NIBBLE_CLOCKS); - if (context->coarse_seek % 3) { - context->next_int_cycle += cd_block_to_mclks(SECTOR_CLOCKS * (3 - (context->coarse_seek % 3))); - } + context->next_int_cycle = cd_block_to_mclks(next_nibble + 7 * NIBBLE_CLOCKS); } } if (context->cycle >= next_nibble) { @@ -721,7 +717,16 @@ } } if (context->cycle >= context->next_byte_cycle) { - if (context->current_sector_byte >= 0 && (!fader->byte_counter || context->current_sector_byte)) { + if (context->current_sector_byte >= 0/* && (!fader->byte_counter || context->current_sector_byte)*/) { + if (!context->current_sector_byte) { + //HACK: things can get a little out of sync currently which causes a mess in the fader code + // since it expects even multiples of 4 bytes (1 stereo sample) + while (fader->byte_counter) + { + lc8951_write_byte(cdc, cd_block_to_mclks(context->cycle), 0, 0); + cdd_fader_data(fader, 0); + } + } uint8_t byte = context->media->read(context->media, context->current_sector_byte); if (context->status != DS_PLAY) { byte = 0; @@ -731,10 +736,6 @@ } else { lc8951_write_byte(cdc, cd_block_to_mclks(context->cycle), 0, 0); cdd_fader_data(fader, 0); - if (context->current_sector_byte >= 0) { - next_subcode += BYTE_CLOCKS; - context->last_sector_cycle += BYTE_CLOCKS; - } } if (context->current_sector_byte == 2352) { context->current_sector_byte = -1;