ALS300 Datasheet, PDF (44/66 Pages) List of Unclassifed Manufacturers – Media Audio Controller SPEC

Avance Logic Inc.
ALS300
1.Program ESP to switch to normal DMA mode transfer. At the end of the current DMA
transfer, ESP will exit from continuous DMA mode and continue to transfer using the
specified normal DMA mode.
2.Send the exit continuous command. The ESP will exit continuous DMA mode at the end of
current block and terminate the transfer.
2.3 Special DMA Mode
Once ESP is in the special DMA mode, it will not accept any further commands or data until the DMA
mode is terminated by
Either
1. Non-continuous special DMA mode will exit special DMA mode automatically at the end of
transfer.
Or
2. For continuous special DMA mode, a ESP_RESET() is needed to exit special DMA mode.
The ESP_RESET() will only stop special DMA transfer, all other parameters remain the same.
I/O Transfer Rate Setup:
Either
1. Sound Blaster Pro (time constant)
Time constant = 256d - (1,000,000d / ( channel * sampling rate))
Channel = 1 for mono or BX,CX type DMA command, 2 for stereo
a. ESP_WRITE(40h)
b. ESP_WRITE(time constant)
Or
2. Sound Blaster 16 (sampling frequency)
Output:
a. ESP_WRITE(41h)
b. ESP_WRITE(frequency.high)
c. ESP_WRITE(frequency.low)
Sampling frequency = 4 KHz to 48 KHz, either mono or stereo
MPU-401 MIDI Programming:
1. MPU-401 pass-thru mode
After reset, midi is in pass-thru mode. MIDIIN data is directly connected to MIDIOUT data.
Any write to midi-data will be ignored. MIDI-COMMAND will support either MIDI_RESET (0FFh) or
ENTER_UART (03Fh).
Both command will return with interrupt and acknowledge byte (0FEh).
2. MPU-401 UART mode
After enter UART mode, all write to midi-data will go to MIDIOUT FIFO, any MIDIIN data will go to
MIDIIN FIFO. (In Special MIDI mode, any write to MIDI-DATA will go to MIDIOUT RAM)
MIDI-STATUS bit 7 = MIDIIN FIFO empty.
MIDI-STATUS bit 6 = MIDIOUT FIFO full + MIDIOUT FIFO not empty when MIDI_RESET
MIDI-STATUS bit 5 = MIDIOUT RAM full
MIDI INTERRUPT =( MIDIIN FIFO not empty & not I/O read(MIDI-DATA))
or (MIDIOUT RAM is not empty in special MPU401 mode)
To end the UART mode, send MIDI_RESET (0FFh) to midi-command port. MIDIIN FIFO will be
flushed, any data in MIDIOUT FIFO/MIDIOUT RAM will be output. When both FIFO are empty,
MPU-401 will enter pass-thru mode .
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