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XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
IIC-Bus Module
User’s Manual
20-3
V2.2, 2004-01
IIC_X, V2.0
Note: Per definition, an IIC-Bus system is a Wired-AND configuration. The active
(dominant) level is the low level, while the high level is not actively driven by the
stations (or nodes), but held through external pull-up devices. For this purpose,
the respective pin drivers must be switched to open drain mode.
Figure 20-2
IIC-Bus Configuration Example
In an IIC-Bus system, a station may be able to play different roles: Master-Transmitter
(a master device which is sending data to one or more slaves), Master-Receiver (a
master which is receiving data from a slave), Slave-Transmitter (a slave which is sending
data to a master) and Slave-Receiver.
MCA05464
SDA0
SCL0
SDA1
SCL1
On-Chip
IIC-Bus
Module
IIC Bus
Node #y
IIC Bus
Node #x
IIC-Bus A
IIC-Bus B