BGS3 Hardware Interface Description
3.11 Audio Interfaces
63
BGS3_HD_v01.000d
Page 57 of 109
2010-03-26
Confidential / Released
For the PCM interface configuration the parameters <clock>, <mode> and <framemode> of the
AT^SAIC command are used. The following table lists possible combinations:
In all configurations the PCM interface has the following common features:
•
16 Bit linear
•
8kHz sample rate
•
the most significant bit MSB is transferred first
•
125µs frame duration
•
common frame sync signal for transmit and receive
shows the assignment of the DAI0...6 signals to the PCM interface signals. To avoid
hardware conflicts different lines are used as inputs and outputs for frame sync and clock sig-
nals in master or slave operation. The table shows also which line is used for master or slave.
The data lines (TXDAI and RXDAI) however are used in both modes. Unused inputs should be
tied to GND via pull down resistors. In addition, DAI1 requires a 47kOhm pull down resistor to
be placed as close as possible to the module. Unused outputs must be left open.
Table 17:
Configuration combinations for the PCM interface
Configuration
<clock>
<mode>
<framemode>
Master, 256kHz, short frame 0
0
0
Master, 256kHz, long frame
0
0
1
Master, 512kHz, short frame 1
0
0
Master, 512kHz, long frame
1
0
1
Slave, 256kHz, short frame
0 or 1
1
1. In slave mode the BCLKIN signal is directly used for data shifting. Therefore, the clock frequency setting
is not evaluated and may be either 0 or 1.
1
0
Slave, 256kHz, long frame
0 or 1
1
1
Slave, 512kHz, short frame
0 or 1
1
0
Slave, 512kHz, long frame
0 or 1
1
1
Table 18:
Overview of DAI signal functions
Signal name
Function for PCM Interface
Input/Output
DAI0
TXDAI
Master/Slave
O
DAI1
RXDAI
Master/Slave
I
DAI2
FS (Frame sync)
Master
O
DAI3
BITCLK
Master
O
DAI4
FSIN
Slave
I
DAI5
BCLKIN
Slave
I
DAI6
nc
I
