User's Manual l MBa8x UM 0100 l © 2021, TQ-Systems GmbH
Page 24
Table 11:
Functions port expander
Port
Signal
Type
Default
Remark
IO_0
Unused
I
Hi-Z
IO_1
LED_A
O
Low
IO_2
LED_B
O
Low
IO_3
Unused
I
Hi-Z
IO_4
DSI_EN
O
Low
IO_5
USB_RESET#
O
High
Default: not used (RESET_OUT# is used)
IO_6
V_12V_EN
O
Low
IO_7
PCIE_DIS#
O
High
3.12
Temperature sensor
A temperature sensor SE97BTP is populated on the MBa8x to monitor the temperature. The same type of sensor is also used on
the TQMa8x. Both sensors are read out via I2C1.
The sensor address on the MBa8x can be changed by reassembling resistors. When changing the address, care must be taken to
avoid address conflicts with existing I
2
C devices. The assembly options are documented in the MBa8x schematics.
The SE97BTP has an additional EEPROM. Further specifications of the SE97BTP can be found in the data sheet.
3.13
Further devices
In addition to the port expander and the temperature sensor, more devices are connected to the I2C1.
These are described in the respective sections for the corresponding interfaces.
3.14
Interfaces
3.14.1
Audio
The audio codec used is the TLV320AIC3204 from Texas Instruments. It is connected to the TQMa8x via SAI (configured as I
2
S)
and I
2
C. The audio codec provides microphone, line in and line out signals. The signals can be accessed via colour coded 3.5 mm
jacks ( green for line-out/headphone, blue for line-in and pink for microphone). A placement option allows to choose between
line out and headphone. Table 12 describes the configuration.
TQMa 8x
SAI1
I2C1
Audio
Codec
TLV320
3,5 mm
socket
3,5 mm
socket
3,5 mm
socket
Microphone
Headphone
Line-In
Figure 10: Block diagram Audio
Table 12:
Placement option Audio
Mode
R77
R78
R79
R80
Remark
Line-Out
0R0
0R0
NP
NP
Default
Headphone
NP
NP
0R0
0R0
Optional
1:
Intended port configuration.
2:
Pull-Ups or Pull-Downs on MBa8x.