C-Media CM6533, Manual

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CM6533,CM6533N,CM6533X1,CM6533DH
USB Audio Chip
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Rev.1.7 Copyright© C-Media Electronics Inc.
Preamble Aux Data LSB Audio Data MSB V U C P
0 3 4 7 8 27 28 29 30 31
Sub-frame
V: Valid, U:User-Data, C:Channel-Status-Data, P:Parity-Bit
Figure -1 SPDIF Subframe Description
In each block, 384 bits of channel status and subcode info are transmitted. The Channel-status bits are equal for both
subframes, so actually only 192 useful bits are transmitted:
ChannelA M ChannelA W ChannelA B ChannelA W ChannelA M ChannelA W
Frame 191 Frame 0 Frame 1
SubFrame SubFrame
Figure -2 Preamble Description of 192 SPDIF frame
6.6.2 SPDIF Out Channel Status
bit0 bit1 bit2 bit3 bit4 bit5 bit6 bit7
byte0
consumer
/professional
audio/
non-audio
copyright pre-emphasis mode
default 0(P) 0(P) 1(P) 0(P) 0(fixed) 0(fixed) 0(fixed) 0(fixed)
byte1 category code L
default 0(P) 0(P) 0(P) 0(P) 0(P) 0(P) 0(P) 0(P)
byte2 source number channel number
default 0(fixed) 0(fixed) 0(fixed) 0(fixed) 0(fixed) 0(fixed) 0(fixed) 0(fixed)
byte3 sampling frequency clock accuracy reserved
default 0(P) 0(P) 0(P) 0(P) 0(fixed) 0(fixed) 0(fixed) 0(fixed)
**Note: (P) These bits can be programmed by USB HID or USB vendor command