Motorola PowerQUICC II MPC8280 Series Reference Manual page 1379

Chapter 40
2
I C Controller
The inter-integrated circuit (I
I 2 C devices, such as microcontrollers, EEPROMs, real-time clock devices, A/D converters,
and LCD displays. The I
several integrated circuits on a board. It uses two signals—serial data (SDA) and serial
clock (SCL)—to carry information between the integrated circuits connected to it.
As shown in Figure 40-1, the I
independent baud-rate generator (BRG), and a control unit. The transmit and receive
sections use the same clock, which is derived from the I
generated externally when in slave mode. Wait states are inserted during a data transfer if
SCL is held low by a slave device. In the middle of a data transfer, the master I
recognizes the need for wait states by monitoring SCL. However, the I
automatic time-out mechanism if the slave device does not release SCL; therefore, software
should monitor how long SCL stays low to generate bus timeouts.
Rx Data Register
Shift Register
MOTOROLA
Freescale Semiconductor, Inc.
2 C®) controller lets the MPC8280 exchange data with other
2 C controller uses a synchronous, multimaster bus that can connect
2
C controller consists of transmit and receive sections, an
Peripheral Bus
Tx Data Register
Shift Register
Control
Baud-Rate Generator
2
Figure 40-1. I C Controller Block Diagram
Chapter 40. I
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2 C BRG when in master mode and
60x Bus
Mode Register
2
C Controller
2 C controller
2 C controller has no
SDA
SCL
40-1