User Manual

CS4202

DS549PP2 33

4.15 S/PDIF Control Register (Index 3Ah)

V Validity. The V bit is mapped to the V bit (bit 28) of every sub-frame. If this bit is ‘clear’, the

signal is suitable for conversion or processing.

DRS Double Rate S/PDIF. The DRS bit is mapped to bit 27 of the channel status block. This bit

controls support for optional h igher sample rate transmission . The CS4202 does n ot support

double rate S/PDIF transmission, therefore DRS is a read-only bit and always retu rns ‘0’.

SPSR[1:0] S/PDIF Sample Rate. The SPSR[1:0] bits are mapped to bits 24 and 25 of the channel status

block. These bits control the S/PDIF transmitter clock rate. The CS4202 only supports tran s-

mission at the standard 48 kHz rate, therefore SPSR[1:0] are read-only bits and always

return ‘10’.

L Generation Status. The L bit is mapped to bit 15 of the channel status block. For category

codes 001xxxx, 0111xxx and 100xxxx, a value of ‘0’ indicates original material and a value of

‘1’ indicates a copy of original material. For all other category codes the definition of the L bit

is reversed.

CC[6:0] Category Code. The CC[6:0] bits are mapped to bits 8-14 of the channel status block.

PRE Data Pr e-emphasis. The PRE bit is mapped to bi t 3 of the channel status block. If the PRE bit

is ‘set’, 50/15 µs filter pre-emphasis is indicated . If the bit is ‘clear’, no pre-emphasis is indi-

cated.

COPY Copyright. The COPY bit is mapped to bit 2 of the channel status block. If the COPY bit is ‘set’

/AUDIO Audio / Non-Audio. The /AUDIO bit is mapped to bit 1 of the channel status block. If the

/AUDIO bit is ‘clear’, the data transmitted over S/PDIF is assumed to be digital audio. If the

/AUDIO bit is ‘set’, non-audio data is assumed.

PRO Professional/Consumer. The PRO bit is mapped to bit 0 of the channel status block. If the

PRO bit is ‘clear’, consumer use of the audio control block is indicated. If the bit is ‘set’, pro-

fessional use is indicated.

Default 2000h

For a further discussion of the prope r use of the cha nnel status bits see application no te AN22: Overview of Digital

Audio Interfac e Dat a Str uct ur es [3]

D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0

V DRS SPSR1 SPSR0 L CC6 CC5 CC4 CC3 CC2 CC1 CC0 PRE COPY /AUDIO PRO