MCCIRM Freescale Semiconductor / Motorola, MCCIRM Datasheet - Page 34

• Manufacturer Part Number: MCCIRM
• Description: MCCIRM Multi-Channel Communications Interface Reference Manual
• Manufacturer: Freescale Semiconductor / Motorola

Configuration and Control
3.7 Pin Control and General-Purpose I/O
Reference Manual
34
The eight pins used by the SPI and SCI subsystems have alternate
functions as general-purpose I/O pins. Configuring the MCCI submodule
includes programming each pin for either general-purpose I/O or its
serial interface function. In either function, each pin also must be
programmed as input or output.
The MCCI data direction register (MDDR) assigns each MCCI pin as
either input or output.
The MCCI pin assignment register (MPAR) assigns the MOSI, MISO,
and SS pins as either SPI pins or general-purpose I/O. (The fourth pin,
SCK, is automatically assigned to the SPI whenever the SPI is enabled,
for instance, when the SPE bit in the SPI control register is set.)
The receiver enable (RE) and transmit enable (TE) bits in the SCI control
registers (SCCR0A and SCCR0B) automatically assign the associated
pin as an SCI pin when set or general-purpose I/O when cleared.
Table 3-3
RXDA/PMC6
RXDB/PMC4
TXDA/PMC7
TXDB/PMC5
MOSI/PMC1
MISO/PMC0
Freescale Semiconductor, Inc.
SCK/PMC2
SS/PMC3
For More Information On This Product,
Pin
summarizes how pin function and direction are assigned.
Go to: www.freescale.com
Configuration and Control
Function Assigned By
Table 3-3. Pin Assignments
RE bit in SCCR0A
RE bit in SCCR0B
TE bit in SCCR0A
TE bit in SCCR0B
MOSI bit in MPAR
MISO bit in MPAR
SPE bit in SPCR
SS bit in MPAR
Multichannel Communication Interface — Rev. 1.0
Direction Assigned By
MDDR7
MDDR6
MDDR5
MDDR4
MDDR3
MDDR2
MDDR1
MDDR0
MOTOROLA