Cirrus Logic CS4207 - Manual (Page 69)

DS880F4 69
CS4207
6.6.10 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,” on an input PCM stream of less than 32 bits, the codec strips off the SIC bits before
transferring the samples to the system and puts them in the Digital Converter Control for later software
access.
In the second case, referred to as “Software Formatted (or Raw) SPDIF,” on a 32-bit input stream, the
entire stream is transferred into the system without the codec stripping any bits. However, the codec must
properly interpret the Sync Preamble bits of the stream and then send the appropriately coded preamble.
The IEC 60958 specification, Section 4.3, “Preambles,” defines the preambles 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 Node ID = 07h Verb ID = F0Dh/** Payload = 00h
Bits [31:28] Bits [27:20] Bits [19:8] Bits [7:0]
CAd = X Node ID = 07h Verb ID = 70Dh Payload = xxh (SIC bits [7:0])
CAd = X Node ID = 07h 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 Only 0000000b
CC[6:0] (Category Code): Programmed accord-
ing to IEC standards, or as appropriate.
7 Read Only 0b
L (Generation Level): Programmed according to
IEC standards, or as appropriate.
6 Read Only 0b
PRO (Professional): 1 indicates Professional use
of channel status; 0 indicates Consumer.
5 Read Only 0b
/AUDIO (Non-Audio): 1 indicates data is non-
PCM format; 0 indicates data is PCM.
4 Read Only 1b
COPY (Copyright): 1 indicates copyright is
asserted; 0 indicates copyright is not asserted.
3 Read Only 1b
PRE (Pre-emphasis): 1 indicates filter pre-
emphasis is 50/15 us; 0 pre-emphasis is none.
2 Read Only 0b
VCFG (Validity Config.): This bit is only defined
for Output Converters and is Reserved, with a
Read Only value of 0 for Input Converters.
1 Read Only 0b
V (Validity): This bit reflects the “Validity flag,”
transmitted in each subframe.
0 Read/Write 0b
DigEn (Digital Enable): Enables or disables digi-
tal transmission. A 1 indicates that the digital
data can pass through the node. A 0 indicates
that the digital data is blocked from passing
through the node, regardless of the state.