MPC823 datasheet(52/74 Pages) MOTOROLA

52 / 74 page

Communication Processor Module

16-430

MPC823 REFERENCE MANUAL

MOTOROLA

16.11.8.6 SMCx GCI MASK REGISTER. When a serial management controller is in GCI

mode, the 8-bit, memory-mapped, read/write SMCx mask register is referred to as the SMCx

GCI mask (SMCM–GCI) register. It has the same bit format as the SMCE–GCI register. If a

bit in this register is a 1, the corresponding interrupt in the SMCE–GCI is enabled. If the bit

is zero, the corresponding interrupt in the SMCE–GCI is masked.

16.12 THE SERIAL PERIPHERAL INTERFACE

The serial peripheral interface (SPI) allows the MPC823 to exchange data between other

MPC8xx microprocessors, the MC68328, MC68360, and MC68302 embedded

microprocessors, as well as the MC68HC11 and MC68HC05 microcontroller families and a

variety of peripheral devices.

The serial peripheral interface is a full-duplex, synchronous, character-oriented channel that

supports a four-wire interface (receive, transmit, clock and slave select). The SPI block

consists of transmitter and receiver sections, an independent baud rate generator, and a

control unit. The transmitter and receiver sections use the same clock, which is derived from

the SPI baud rate generator in master mode and generated externally in slave mode. During

an SPI transfer, data is transmitted and received simultaneously.

Because the SPI receiver and transmitter are double-buffered, as illustrated in the block

diagram below, the effective FIFO size is 2 characters. You can program the MPC823 serial

peripheral interface to shift out the most- or least-significant bit first. When the serial

peripheral interface is not enabled in the SPMODE register, it consumes very little power.

SMCM–GCI

BIT

FIELD

RESERVED

CTXB

CRXB

MTXB

MRXB

RESET

0000

R/W

ADDR

(IMMR & 0xFFFF0000) + 0xA8A (SMC1), 0xA9A(SMC2)

MPC823 Datasheet(PDF) 52 Page - Motorola, Inc