29.2 External signal description
The SPI optionally shares four port pins. The function of these pins depends on the
settings of SPI control bits. When the SPI is disabled (SPE = 0), these four pins revert to
other functions that are not controlled by the SPI (based on chip configuration).
29.2.1 SPSCK — SPI Serial Clock
When the SPI is enabled as a slave, this pin is the serial clock input. When the SPI is
enabled as a master, this pin is the serial clock output.
29.2.2 MOSI — Master Data Out, Slave Data In
When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not
bidirectional mode), this pin is the serial data output. When the SPI is enabled as a slave
and SPC0 is 0, this pin is the serial data input. If SPC0 is 1 to select single-wire
bidirectional mode, and master mode is selected, this pin becomes the bidirectional data
I/O pin (MOMI). Also, the bidirectional mode output enable bit determines whether the
pin acts as an input (BIDIROE is 0) or an output (BIDIROE is 1). If SPC0 is 1 and slave
mode is selected, this pin is not used by the SPI and reverts to other functions (based on
chip configuration).
29.2.3 MISO — Master Data In, Slave Data Out
When the SPI is enabled as a master and SPI pin control zero (SPC0) is 0 (not
bidirectional mode), this pin is the serial data input. When the SPI is enabled as a slave
and SPC0 is 0, this pin is the serial data output. If SPC0 is 1 to select single-wire
bidirectional mode, and slave mode is selected, this pin becomes the bidirectional data I/
O pin (SISO), and the bidirectional mode output enable bit determines whether the pin
acts as an input (BIDIROE is 0) or an output (BIDIROE is 1). If SPC0 is 1 and master
mode is selected, this pin is not used by the SPI and reverts to other functions (based on
chip configuration).
Chapter 29 Serial Peripheral Interface (SPI)
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
Freescale Semiconductor, Inc.
447