AC’97 Controller Unit

Table 13-5. Input Slot 1 Bit Definitions (Sheet 2 of 2)

4

3

2

1,0

Slot 10 request: NA

Slot 11 request: NA

Slot 12 request: NA

reserved (Filled with zero)

SLOTREQ bits are independent of the Control Register Index bits.

Note: Slot requests for Slot 3 and Slot 4 are always set or cleared in tandem (both are set or both are cleared).

13.4.2.3Slot 2: Status Data Port

Slot 2 delivers 16-bit control register read data.

Table 13-6. Input Slot 2 Bit Definitions

Bit

Name

Description

 

 

 

Bit(19:4)

Control register read data

Filled with data

 

 

 

Bit(3:0)

reserved

Filled with zeroes

 

 

 

Note: If Slot 2 is tagged invalid, the CODEC fills the entire slot with zeroes.

13.4.2.4Slot 3: PCM Record Left Channel

Slot 3 contains the CODEC left channel output.

The CODEC transmits its ADC output data (MSB first) and fills any trailing non-valid bit positions with zeroes.

13.4.2.5Slot 4: PCM Record Right Channel

Slot 4 contains the CODEC right-channel output.

The CODEC transmits its ADC output data (MSB first), and fills any trailing non-valid bit positions with zeroes.

13.4.2.6Slot 5: Optional Modem Line CODEC

Slot 5 contains MSB justified line modem ADC output data (if the line modem CODEC is supported).

The ACUNIT only supports a 16-bit ADC output resolution from the optional line modem.

13.4.2.7Slot 6: Optional Dedicated Microphone Record Data

Slot 6 contains an optional third PCM system-input channel available for dedicated use by a microphone. This input channel supplements a true stereo output to enable a more precise echo- cancellation algorithm for speakerphone applications.

Intel® PXA255 Processor Developer’s Manual

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Intel PXA255 manual Slot 2 Status Data Port, Slot 3 PCM Record Left Channel, Slot 4 PCM Record Right Channel