LSI Logic Confidential
Audio Input Control Register
12-3
Copyright © 2001, 2002 by LSI Logic Corporation. All rights reserved.
When carrying PCM audio samples, IEC-958 groups data into a series
of blocks. Each block contains 192 frames. Each frame contains
2 subframes and each subframe contains a data payload of one audio
sample. When carrying mono signals, the same audio sample can be
used for both subframes. The start of a block is designated by a special
subframe sync preamble.
12.2 Audio Input Control Register
The Audio Input Control Register is used to control a variety of features,
as described below. A read-modify-write cycle should be used when
accessing this register.
Audio Input Control Register
Cbus Address: 0x50004
Iclkr
25
Specifies the clock polarity for audio input stream 1
signals. Input signals are sampled on the opposite edge
that output signals are driven. If set, audio input stream 1
serial data and frame sync input (AI_D[3:0], AI_FSYNC
as an input) are clocked on the rising edge of the
AI_SCLK input; otherwise, they are clocked on the falling
edge. If set, audio input stream 1 frame sync output
(AI_FSYNC as an output) is clocked on the falling edge
of the AI_SCLK input; otherwise, it is clocked on the
rising edge. Programming note: This field should be
31
26
25
24
23
22
21
20
18
17
16
Reserved
Icklr
IBclk
Stop
Res
FrForm
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FrForm
0
ISync
ITim
Res
IS32
LE
ChCnt
AudInt
Res
IQF
0
GoI