Module cd 

CD-ROM drive: commands, responses, sector polling, CD-DA playback in audio, XA-ADPCM music in xa and polled data-sector reads in reader.

One driver owns the controller: the Cd token. Every command and register step is a method taking &mut Cd, so the borrow checker sees a second driver that tries to program the controller while one is mid-command. xa::Player and reader::SectorReader hold the token while they exist and give it back with release.

The controller exposes four byte registers selected by the low two bits of the index register at [psx_hw::cd::reg::INDEX]. Register addresses, command bytes and status bits live in [psx_hw::cd].

Modules

audio

CD-DA playback helpers: a start-handshake state machine and an audio-anchored clock.

reader

Polled CD-ROM data-sector reads: seek, stream and pop 2048-byte sectors.

xa

XA-ADPCM music: stream one channel of an interleaved XA file through the drive’s own decoder to the SPU’s CD input.

Structs

PlayPosition

Decoded CdlGetlocP reply. The relative MSF (relative_*) is elapsed time into the current track, independent of the pregap, which makes it the source of truth for a music/song clock. The absolute MSF (absolute_*) is the raw disc position.

Response

Fixed-size command response.

SectorPollError

A drive error reported while polling for the next streamed sector.

Enums

CdError

Why a CD command produced no response.

Constants

DEFAULT_COMMAND_SPINS

Poll budget the blocking commands give the controller for each wait (a parameter slot, then the acknowledge). Generous: the controller frees a slot and acknowledges within microseconds to milliseconds, so this is a hang guard, not a latency.

Functions

acknowledge_irqDeprecated

Moved to Cd::acknowledge_irq.

bcd_to_bin

Convert a BCD byte back to binary. Inverse of bin_to_bcd for well-formed input; nibbles above 9 are not normalised (the drive never emits them).

bin_to_bcd

Convert binary 0..=99 to BCD for CD-ROM command parameters.

discard_responseDeprecated

Moved to Cd::discard_response.

dispatch_commandDeprecated

Moved to Cd::dispatch_command.

irq_flag_valueDeprecated

Moved to Cd::irq_flag_value.

lba_to_bcd_msf

Data-track LBA to the absolute BCD [minute, second, frame] Setloc takes. LBA 0 is 00:02:00: the 150-sector lead-in puts it two seconds in. Minutes clamp at 99.

poll_data_sectorDeprecated

Moved to Cd::poll_data_sector.

restore_irq_outputDeprecated

Moved to Cd::restore_irq_output.

try_commandDeprecated

Moved to Cd::try_command.

try_muteDeprecated

Moved to Cd::try_mute.

try_pauseDeprecated

Moved to Cd::try_pause.

try_pause_until_completeDeprecated

Moved to Cd::try_pause_until_complete.

try_play_positionDeprecated

Moved to Cd::try_play_position.

try_play_trackDeprecated

Moved to Cd::try_play_track.

try_set_modeDeprecated

Moved to Cd::try_set_mode.

try_set_target_lbaDeprecated

Moved to Cd::try_set_target_lba.

try_start_readingDeprecated

Moved to Cd::try_start_reading.

try_statusDeprecated

Moved to Cd::try_status.

try_unmuteDeprecated

Moved to Cd::try_unmute.