DSB45 Development Support Box
Confidential / Released
s
DSB45_HD_V05
Page 23 of 50
01.02.2008
2.7.5.3
Digital audio interface (DAI)
For GSM modules equipped with a DAI the DSB45 provides two solutions to connect an
appropriate device. Both solutions are mutually exclusive:
•
10-pin X203 connector if the slide switches X116 - X120 are set to position “Internal” as
described in Chapter 2.7.1.
The DAI clock slide switch X204 is accessible.
•
40-pin connector X152 if the slide switches X116 - X120 set to position “External” as
described in Chapter 2.7.2.
The DAI clock slide switch X204 is not accessible.
The serial DAI transfers PCM digital audio data between the GSM module and the host
application. The DAI of the GSM module is designed for use with a codec or a DSP. A
detailed description of the DAI can be found in [1].
Table 10: Pin assignment of the DAI interface X203 on DSB45
Pin no.
Designation
I/O
Function
1
CLKSXM _OUT
O
Reserved for future use, keep pin open.
2
DSPOUT_OUT
O
Reserved for future use, keep pin open.
3
SCLK_OUT
I
Shift clock to GSM module (module is slave), 0.2 to 20 MHz
4
GND
Signal ground
5
TXDDDAI_OUT
O
Transmit data
6
TFSDAI_OUT
O
Transmit frame sync (module is master)
7
RXDDAI_OUT
I
Receive data
8
RFSDAI_OUT
I
Receive frame sync (module is slave)
9 NC
Not
connected
10 NC
Not
connected
Note for MC55i only:
If you wish to test the module’s DAI please ensure that the device (a codec or a DSP)
connects only to the pins 25 - 30 of the external 40-pin connector X152 on the DSB45. It is
not possible to use the internal 10-pin DAI connector X203 and the DAI clock switch X204 on
the DSB45. Please note that operating the DAI with the X116 - X120 slide switches set to
“Internal” position will cause damage to the DAI interfaces on the MC55i module and on the
DSB45.
