xe3006 Semtech Corporation, xe3006 Datasheet - Page 13

• Manufacturer Part Number: xe3006
• Description: Sandman? Codec | Semtech
• Manufacturer: Semtech Corporation

3
3.1
The Serial Audio Interface is a 4-wire interface for bi-directional communication of audio data. The 4 terminals are listed
below:
The same clock (BCLK) and synchronization (FSYNC) signals are used for both sending and receiving. The
synchronization signal FSYNC must have a fixed ratio with the master clock signal MCLK.
The Serial Audio Interface supports two formats that are commonly used for audio/voice CODECs and that are referred to
as SFS (Short Frame Synchronization) and LFS (Long Frame Synchronization). Data can be transmitted and received in
2 channels. Which channel is selected depends on the programmed values in the registers. The two interface protocols
are shown below.
© Semtech 2005
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SERIAL COMMUNICATIONS
SERIAL AUDIO INTERFACE
FSYNC
FSYNC
BCLK:
FSYNC:
SDI:
SDO:
BCLK
BCLK
SDO
SDO
SDI
SDI
Bit serial clock, one clock cycle corresponds to one data bit transmitted or received.
Frame Synchronization. This signal indicates the start of a data word. The frequency of the FSYNC
corresponds to the sample frequency of the CODEC.
Serial Data In, data received from external device and sent to DAC.
Serial Data Out, data received from ADC and sent to external device.
msb
msb
n
n
n
n
15
15
15
15
n
n
channel 1, sample n
n
n
Figure 14: Audio interface timing in SFS mode, channel 1
14
14
channel 1, sample n
14
14
Figure 13: Audio interface timing LFS mode, channel 1
lsb
n
n
lsb
n
n
0
0
0
0
-
13
-
-
-
-
-
-
-
channel 2, no data
channel 2, sample n
XE3005/XE3006
-
-
-
-
msb
n+1
channel 1, sample n+1
n+1
msb
n+1
channel 1, sample n+1
n+1
15
15
15
15
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