CS4299-BQZR Cirrus Logic Inc, CS4299-BQZR Datasheet - Page 14

• Manufacturer Part Number: CS4299-BQZR
• Description: IC AC97 Codec With SRC
• Manufacturer: Cirrus Logic Inc

3.1
In the serial data output frame, data is passed on the SDATA_OUT pin to the CS4299-BQ from the AC
’97 controller. Figure 9 illustrates the serial port timing.
The PCM playback data being passed to the CS4299-BQ is shifted out MSB first in the most significant
bits of each slot. Any PCM data from the AC ’97 controller that is not 20 bits wide should be left justified
in its corresponding slot and dithered or zero-padded in the unused bit positions.
Bits that are reserved should always be ‘cleared’ by the AC ’97 controller.
3.1.1 Serial Data Output Slot Tags (Slot 0)
Valid Frame
Slot [1:2] Valid
Slot [3:10] Valid
Codec ID[1:0]
14
14
Frame
Bit 15
Valid
AC-Link Serial Data Output Frame
Slot 1
Valid
14
Slot 2
Valid
13
for the CS4299-BQ DACs or data for read/write operations. When ‘set’, at least one of the other
AC-link slots contain valid data. If this bit is ‘clear’, the remainder of the frame is ignored.
slots. If a bit is ‘set’, the corresponding output slot contains valid data. If a bit is ‘cleared’, the
corresponding slot will be ignored.
If a Slot Valid bit is ‘set’, the named slot contains valid audio data. If the bit is ‘clear’, the slot will
be ignored. The CS4299-BQ supports alternate slot mapping as defined in the AC ’97 2.1 spec-
ification. For more information, see the AC Mode Control Register (Index 5Eh).
The Codec ID[1:0] bits display the Codec ID of the audio codec being accessed during the cur-
rent AC-link frame. Codec ID[1:0] = 00 indicates the primary codec is being accessed. Codec
ID[1:0] = 01, 10, or 11 indicates one of three possible secondary codecs is being accessed. A
non-zero value of one or more of the Codec ID bits indicates a valid Read or Write Address in
Slot 1, and the Slot 1 R/W bit indicates presence or absence of valid Data in Slot 2.
The Valid Frame bit determines if any of the following slots contain either valid playback data
The Slot [1:2] Valid bits indicate the validity of data in their corresponding serial data output
The Slot [3:10] Valid bits indicate Slot [3:10] contains valid playback data for the CS4299-BQ.
Slot 3
Valid
12
Slot 4
Valid
11
Slot 5
Valid
10
Slot 6
Valid
9
Slot 7
Valid
8
Slot 8
Valid
7
Slot 9
Valid
6
Slot 10
Valid
5
4
Reserved
3
CS4299-BQ
2
CS4299-BQ
DS319-BQPP2
Codec
ID1
1
Codec
ID0
0