Cirrus Logic CS4207 - Manual (Page 76)

76 DS880F4
CS4207
6.7.8 Digital Converter Control
Get Parameter Command Format:
** Note: Address F0Eh is not supported.
Set Parameter Command Format:
Response Format:
The S/PDIF IEC Control (SIC) bits are supported in one of two ways. In the first case referred to as “Codec
Formatted SPDIF,” if a PCM bit stream of less than 32 bits is specified in the Converter Format control,
then the S/PDIF Control bits, including the “V,” “PRE,” “/AUDIO,” and other such bits are embedded in the
stream by the codec using the values (SIC bits) from the Digital Converter Control.
In the second case referred to as “Software Formatted (or Raw) SPDIF,” if a 32-bit stream is specified in
the Converter Format control, the S/PDIF IEC Control (SIC) bits are assumed to be embedded in the
stream by software, and the raw 32-bit stream is transferred on the link with no modification by the codec.
However, the codec must properly interpret the Sync Preamble bits of the stream and then send the ap-
propriately coded preamble. The IEC60958 specification, Section 4.3, “Preambles,” defines the pream-
bles and the coding to be used. Software will specify the “B,” “M,” or “W” (also known as “X,” “Y,” or “Z”)
preambles by encoding the last four bits of the preamble into the Sync Preamble section (bits 0-3) of the
frame. The codec must examine the bits specified and encode the proper preamble based on the previous
state. The previous state is to be maintained by the codec hardware.
Bits [31:28] Bits [27:20] Bits [19:8] Bits [7:0]
CAd = X S/P Tx 1 Node ID=08h
S/P Tx 2 Node ID=14h Verb ID = F0Dh/** Payload = 00h
Bits [31:28] Bits [27:20] Bits [19:8] Bits [7:0]
CAd = X
S/P Tx 1 Node ID=08h
S/P Tx 2 Node ID=14h Verb ID = 70Dh Payload = xxh (SIC bits [7:0])
CAd = X
S/P Tx 1 Node ID=08h
S/P Tx 2 Node ID=14h Verb ID = 70Eh Payload = xxh (SIC bits [15:8])
Bits Type Default Description
31:16 Read Only 0000h Reserved
15 Read Only 0b Reserved
14:8 Read/Write 0000000b
CC[6:0] (Category Code): Programmed accord-
ing to IEC standards, or as appropriate.
7 Read/Write 0b
L (Generation Level): Programmed according to
IEC standards, or as appropriate.
6 Read/Write 0b
PRO (Professional): 1 indicates Professional use
of channel status; 0 indicates Consumer.
5 Read/Write 0b
/AUDIO (Non-Audio): 1 indicates data is non-
PCM format; 0 indicates data is PCM.
4 Read/Write 0b
COPY (Copyright): 1 indicates copyright is
asserted; 0 indicates copyright is not asserted.
3 Read/Write 0b
PRE (Pre-emphasis): 1 indicates filter pre-
emphasis is 50/15 µs; 0 pre-emphasis is none.