User's Manual l MBa8Xx UM 0100 l © 2020, TQ-Systems GmbH
Page 12
3.3
I
2
C devices
3.3.1
Default I
2
C interface
The TQMa8Xx provides several I
2
C buses, of which only I2C1 is used on the MBa8Xx.
There are more I
2
C devices on the TQMa8Xx, so the already used I
2
C addresses have to be taken into account.
Depending on the application and software load, the number of I
2
C devices used can limit the data throughput or block the bus.
For this reason, the devices used on the MBa8Xx can be optionally connected to the I2C2. This assembly option is described in
the MBa8Xx schematics.
TQMa8Xx
I2C1_SCL
I2C1_SDA
I2C2_SCL
I2C2_SDA
R
266
R
267
Level
Shifter
R371
R372
R373
R374
SN65DSI86
SCL
SDA
4.
7
kΩ
4.
7
kΩ
V_3V3_MB
Header
(X4)
TLV320
SCL
SDA
PCA9538A
SCL
SDA
Header
(X4)
TUSB8041
SCL
SDA
9FGV0241
SCLK
_3
.3
SDATA
_3
.3
SE97BTP
SCL
SDA
Mini PCIe
Slot (X24)
Header
(X5)
2.
2
kΩ
2.
2
kΩ
V_1V8
NP
NP
Figure 3:
Block diagram I
2
C bus
Note: I²C address conflicts
When changing the address due to assembly options or when connecting further I²C components,
it must be ensured that no address conflicts occur. Otherwise malfunctions may occur. The addresses
preassigned by the TQMa8Xx must also be observed (depending on the TQMa8Xx variant used).
