Audioport Interface Registers - Cirrus Logic CS42L42 Manual

7.17 AudioPort Interface Registers

7.17.1 Serial Port Receive Channel Select
R/W
7
Default 0
Bits Name
7:4 — Reserved
3:2 SP_RX_ SP RX Channel B select for DAI0. Selects right input channel. Valid only if the SWIRE_SEL pin is deasserted.See
CHB_SEL for programming examples.
00 Channel 0
1:0 SP_RX_ SP RX Channel A select for DAI0. Selects right input channel. Valid only if the SWIRE_SEL pin is deasserted.
CHA_SEL 00 (Default) Channel 0
7.17.2 Serial Port Receive Isochronous Control
R/W
7
— SP_RX_RSYNC
Default
0
Bits Name
7 — Reserved
6 SP_RX_ Serial port receive synchronization.
RSYNC
0 (Default) Normal state
1 Recenter the FIFO. No read and writes when asserted
5:3 SP_RX_ Serial-port receive null-sample bit position. Selects the position of the null byte in the resultant 16-, 24-, or 32-bit sample.
NSB_
For all samples, if SP_RX_ISOC_MODE ≠ 00, SP_RX_NFS_NSBB = 0, the following applies:
POS
• For a 16-bit sample (8-bit audio + null byte), [23:16] is the null byte.
• For a 24-bit sample (16-bit audio + null byte), [15:8] is the null byte.
• For a 32-bit sample (24-bit audio + null byte), [7:0] is the null byte.
Note: NSB Mode does not support 32-bit audio samples.
The ASP_RXn_CHn_RES fields in
Clearing SP_RX_NSB_POS indicates that Bit 0 must be zero for the sample to be classified as a null.
000 (Default) 0 ... 111 7
2 SP_RX_ Serial-port receive NSB/NFS Mode select.
NFS_
0 NSB Mode valid only if SP_RX_ISOC_MODE ≠ 00.
NSBB
1 (Default) NFS Mode
1:0 SP_RX_ Serial port receive isochronous mode. Selecting an isochronous mode allows for null removal. The ASP Rx rate bits
ISOC_ FS, see p. 158) are used only to help the device determine when to insert nulls.
MODE 00 (Default) Native mode
01 48k isochronous stream
7.17.3 Serial Port Receive Sample Rate
R/W
7
Default 1
Bits Name
7:5 — Reserved
4:0 SP_ SP receive sample rate. Configures the sample rate of the SRC F
RX_ configuring for a isochronous rate of 96 or 192 kHz with respect to the 48-kHz isochronous rate, e.g., 24-kHz setting in
FS isochronous rate of 48 kHz would be scaled to a 48-kHz setting in isochronous rate of 96 kHz.
0 0000 Reserved
0 0001 8.00 kHz
0 0010 11.025 kHz
0 0011 11.0295 kHz
DS1083F2
6 5
—
0 0
01 (Default) Channel 1
01 Channel 1
6 5
SP_RX_NSB_POS
0 0
Section 7.22
6 5
—
0 0
0 0100 12.000 kHz 0 1000 24.000 kHz
0 0101 16.000 kHz 0 1001 32.000 kHz
0 0110 22.050 kHz 0 1010 44.100 kHz
0 0111 22.059 kHz 0 1011 44.118 kHz
4 3
SP_RX_CHB_SEL
0 0
Description
10 Channel 2
10 Channel 2
4 3
SP_RX_NFS_NSBB
0 0
Description
set the output resolution of the ASP receive channel samples.
10 96k isochronous stream
11 192k isochronous stream
4 3
0 1
Description
when in Isochronous Mode. This setting autoscales when
SI
0 1100 (Default) 48.000 kHz
0 1101 88.200 kHz
0 1110 88.236 kHz
0 1111 96.000 kHz
7.17 AudioPort Interface Registers
Address 0x2501
2 1
SP_RX_CHA_SEL
1 0
11 Channel 3
11 Channel 3
Address 0x2502
2 1
SP_RX_ISOC_MODE
1 0
2 1
SP_RX_FS
1 0
1 0000 176.400 kHz
1 0001 176.472 kHz
1 0010 192.000 kHz
1 0011–1 1111 Reserved
CS42L42
0
0
Section 5
0
0
(SP_RX_
Address 0x2503
0
0
158