
Communication Processor Module
MOTOROLA
MPC823 USER’S MANUAL
16-463
I2
C
COMMUNICATION
16
PROCESSOR
MODULE
DATA LENGTH
This field represents the number of octets the communication processor module should
transmit from this buffer descriptor data buffer. However, it is never modified by the
communication processor module. Normally, this value should be greater than zero. The I2C
controller writes these bits after it finishes transmitting the associated data buffer.
TX DATA BUFFER POINTER
This field always points to the first location of the associated data buffer. They can be even
or odd, unless the number of actual data bits in the character is greater than 8 bits, in which
case the transmit buffer pointer must be even. The buffer can reside in internal or external
memory. The I2C controller writes these bits after it finishes transmitting the associated data
buffer.
16.13.7.4 I2C ADDRESS REGISTER. The 8-bit, memory-mapped, read/write I2C address
(I2ADD) register holds the address for this I2C port. You need to program this register if you
are operating in multimaster, slave, or local loopback mode.
SAD— Slave Address 0–6
This field holds the slave address for the I2C port.
Bit 7—Reserved
This bit is reserved and should be set to 0.
I2ADD
BIT
0
1
2
3
4
5
6
7
FIELD
SAD
RESERVED
RESET
00
R/W
R/W
ADDR
(IMMR & 0xFFFF0000) + 0xA64