VS1005g Datasheet
10 VS1005 PERIPHERALS AND REGISTERS
The speed of the S/PDIF transmitter depends on the sampling frequency of the audio signal.
Since S/PDIF signal is often used to retrieve a clock signal at the receiving end, S/PDIF trans-
mitter must produce an exact frequency with a very low jitter.
Supported sampling frequencies are 32 kHz, 48 kHz, 96 kHz and 192 kHz when master clock
frequency is n x 12.288MHz. 44.1 kHz sampling frequency is supported.
10.13.4 S/PDIF Transmitter Registers
S/PDIF supports audio sample width of 16 to 24 bits. The exact figure is conveyed to the
receiver by channel status bits. If the the transmitted sample word is less than 24 bits wide, the
remaining LSB’s must be zero.
Channel status registers provide interface to the S/PDIF standard implementation channel sta-
tus bits. The S/PDIF Transmitter inserts the corresponding bits to their proper places in the
transfer frame. Channel status data (byte 23) for cyclic redundancy check character (CRCC) is
not tested yet.
This document offers a terse description of the channel status bits. Full coverage in IEC 60958-
3 is mandatory. Current implementation shares Channel Status Data bits (registers CHS0 and
CHS1) for both channels!
S/PDIF Transmitter Registers
Reg Type Reset Abbrev
Description
SP_TX_LDATA_LSB Left channel Audio sample bits 7-0
SP_TX_LDATA Left channel Audio sample bits 23-8
SP_TX_RDATA_LSB Right channel Audio bits sample 7-0
0xFD02
0xFD03
0xFD04
0xFD05
0xFD08
0xFD09
0xFD0A
0xFD0B
w
w
w
0
0
0
0
0
0
0
w
SP_TX_RDATA
SP_TX_CHST0
SP_TX_CHST1
SP_TX_CHST2
Right channel Audio sample bits 23-8
Channel Status 0
Channel Status 1
r/w
r/w
r/w
r/w
Channel Status 1
0x40 SP_TX_CFG
Transmitter configuration
SP_TX_LDATA, SP_TX_LDATA_LSB, SP_TX_RDATA and SP_TX_RDATA_LSB registers are
transmitter data registers. S/PDIF data is 24 bits and it is divided in two registers. 16 MSB bits
are in registers SP_TX_LDATA and SP_TX_RDATA. The remaining 8 LSB bits are in registers
SP_TX_LDATA_LSB and SP_TX_RDATA_LSB.
Channel Status SP_TX_CHST0
Name
Bits of data Bits of Chan- Description
word
nel status
SP_CH0_CAT
SP_CH0_MD0
SP_CH0_PCMM
SP_CH0_CP
15:8
7:6
5:3
2
15:8
7:6
5:3
2
Category Code
PCM Mode 0
Linear PCM Mode
Copyright
SP_CH0_PCM
SP_CH0_PROCON
1
0
1
0
Linear PCM
Professional/Consumer
mode
SP_CH0_CAT indicates to which category the device belongs. Default value is “00000000”.
Version: 0.2, 2012-03-16
76
ETC [ ETC ]
