MC9S12T64 Datasheet, PDF (481/608 Pages) Motorola, Inc – Specification

Freescale Semiconductor, Inc.
Serial Peripheral Interface (SPI)
Functional Description
NOTE:
Care must be taken when using the SS output feature in a multimaster
system since the mode fault feature is not available for detecting system
errors between masters.
Bidirectional
Mode (MOMI or
SISO)
The bidirectional mode is selected when the SPC0 bit is set in SPI
control register 2 (see Normal Mode and Bidirectional Mode). In this
mode, the SPI uses only one serial data pin for the interface with
external device(s). The MSTR bit decides which pin to use. The MOSI
pin becomes the serial data I/O (MOMI) pin for the master mode, and the
MISO pin becomes serial data I/O (SISO) pin for the slave mode. The
MISO pin in the master mode and MOSI pin in the slave mode are not
used by the SPI in Bidirectional Mode.
When SPE = 1
Table 84 Normal Mode and Bidirectional Mode
Master Mode MSTR = 1
Slave Mode MSTR = 0
Normal Mode
SPC0 = 0
Serial Out
SPI
Serial In
MOSI
MISO
Serial In
SPI
Serial Out
MOSI
MISO
Serial Out
Bidirectional Mode
SPC0 = 1
SPI
Serial In
BIDIROE
MOMI
Serial In
SPI
Serial Out
BIDIROE
SISO
.
The direction of each serial I/O pin depends on the BIDIROE bit. If the
pin is configured as an output, serial data from the shift register is driven
out on the pin. The same pin is also the serial input to the shift register.
The SCK is output for the master mode and input for the slave mode.
The SS is the input or output for the master mode, and it is always the
input for the slave mode.
Serial Peripheral Interface (SPI)
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MC9S12T64Revision 1.1.1