4.2.1.7.2 Command 41h

Function: Set Playback Sample Rate by Frequency

Sampling Frequency = 4 kHz to 48 kHz, either mono or stereo

4.2.1.7.3 Command 42h

Function: Set Recording Sample Rate by Frequency

Sampling Frequency = 4 kHz to 48 kHz, either mono or stereo

4.2.1.7.4 Command 48h

Function: Set Block Length for Continuous and Special DMA

Length = number of bytes to be transferred - 1

SB ESP will generate an interrupt after the specified block length of data has been transferred.

4.2.1.8 SB ADPCM Playback Only Command 7xh

4.2.1.8.1 Command 72–77h

Function: SB ADPCM normal DMA playback

Length = number of bytes to be transferred - 1

These commands are not supported, the implemented SB ESP engine will behave like its normal operation except silent the out-

put and do not perform the bus mastering operation.

4.2.1.8.2 Command 7A–7Fh

Function: SB ADPCM continuous DMA playback

These commands are not supported, the implemented SB ESP engine will behave like its normal operation except silent the out-

put and do not perform the bus mastering operation.

4.2.1.9 Output Silence Command 8xh

4.2.1.9.1 Command 80h

Function: Silence Digital Audio for a Duration

Duration = number of sample rate count - 1

After the specified duration elapses, SB ESP will generate an interrupt. During silence period, SB ESP output middle range data

to CODEC (8000h).

4.2.1.10 Special DMA Playback/Recording Command 9xh

All special DMA mode use command 48h to set the transfer block size. The non-continuous special DMA mode will interrupt the

CPU at the end of the transfer block and wait for new command. Use SB ESP_Reset( ) to end the continuous special DMA, all

other parameters remain the same after the SB ESP_Reset( ).

SB ESP uses SBMX0E.1 to do mono/stereo playback.

SBMX0E.1 = 0 for mono playback

1 for stereo playback

MX0E.1 default value is 0 after power up reset or mixer reset

SB ESP uses command A0h/A8h to set mono/stereo recording state.

Mono recording after SB ESP command A0h

Stereo recording after SB ESP command A8h

Default recording state after power up reset or ESP_Reset() is mono.

4.2.1.10.1 Command Bit Definition

Bit 3

0 Special DMA Playback

1 Special DMA Recording

Bit 2 X reserved

Bit 1 X reserved

Bit 0

0 Continuous DMA

1 Non-Continuous DMA

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