GS2972 Datasheet, PDF (47/125 Pages) Semtech Corporation – 3G/HD/SD-SDI Serializer with Complete SMPTE Audio & Video Support

4.7.2 Serial Audio Data Format Support
The GS2972 supports the following serial audio data formats:
• I²S Audio (default)
• AES/EBU
• Serial Audio, Left Justified, MSB First
• Serial Audio, Left Justified, LSB First
• Serial Audio, Right Justified, MSB First
• Serial Audio, Right Justified, LSB First
By default (at power up or after system reset), the I²S data format is enabled.
The audio format can be different for both audio groups. Normally, AIN_1/2 and
AIN_3/4 are embedded in Audio Group A, and AIN_5/6 and AIN_7/8 are embedded in
Audio Group B. As well, the audio formats can be different within the same group.
Under normal conditions:
AMA sets the audio format for AIN_1/2
AMB sets the audio format for AIN_3/4
AMC sets the audio format for AIN_5/6
AMD sets the audio format for AIN_7/8
Note: These four formats can all be set to different modes if desired.
Table 4-7 shows the audio input formats for the GS2972. Note that the same values apply
for AMB + LSB_FIRSTB, AMC + LSB_FIRSTC and AMD + LSB_FIRSTD.
Table 4-7: Audio Input Formats
AMA[1:0]
(Address 40Bh for SD,
Address 80Ah for HD/3G)
00
01
01
10
10
11
LSB_FIRSTA
(Address 40Fh for SD,
Address 80Eh for HD/3G)
X
0
1
0
1
X
Audio Input Formats
AES/EBU audio input
Serial audio input: Left Justified; MSB first
Serial audio input: Left Justified; LSB first
Serial audio input: Right Justified; MSB first
Serial audio input: Right Justified; LSB first
1²S (default)
WCLK
ACLK
AIN[8/7:2/1]
23 22
MSB
Channel A (Left)
6 5 43 2 10
LSB
Figure 4-21: I²S Audio Input Format
Channel B (Right)
23 22
MSB
65 4 32 10
LSB
GS2972 3G/HD/SD-SDI Serializer with Complete
SMPTE Audio & Video Support
Final Data Sheet Rev. 9
GENDOC-047479 September 2013
www.semtech.com
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