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Parallel Input/Output
MC9S08RC/RD/RE/RG Data Sheet, Rev. 1.11
Freescale Semiconductor
75
6.3.3
Port C
Figure 6-3. Port C Pin Names
Port C is an 8-bit general-purpose I/O port with four pins shared with the KBI2 keyboard interrupt inputs
and four pins shared with the SPI.
Port C pins are available as general-purpose I/O pins controlled by the port C data (PTCD), data direction
information about general-purpose I/O control.
When the SPI module is enabled, PTC7 serves as the SPI module’s slave select pin (SS1), PTC6 serves as
the SPI clock pin (SPSCK1), PTC5 serves as the master-in slave-out pin (MISO1), and PTC4 serves as the
master-out slave-in pin (MOSI1). Refer to the Serial Peripheral Interface (SPI) Module chapter for more
information about using PTC7–PTC4 as SPI pins.
Any of the port C pins PTC3-PTC0 can be congured as a KBI2 keyboard interrupt pin. Refer to the
Keyboard Interrupt (KBI) Module chapter for more information about using port C pins as keyboard
interrupt pins.
6.3.4
Port D
Figure 6-4. Port D Pin Names
Port D is an 7-bit general-purpose I/O port with one pin shared with the BKGD/MS function, one pin
shared with the RESET function, one pin shared with the IRQ function, and one pin shared with the TPM.
Port D pins are available as general-purpose I/O pins controlled by the port D data (PTDD), data direction
information about general-purpose I/O control.
The PTD0/BKGD/MS pin is congured for the BKGD/MS function during reset and following reset. The
internal pullup for this pin is enabled when the BKGD/MS function is enabled, regardless of the PTDPE0
bit. During reset, the BKGD/MS pin functions as a mode select pin. After the MCU is out of reset, the
BKGD/MS pin becomes the background communications input/output pin. PTD0 can be congured to be
information about using this pin.
The PTD1/RESET pin is congured for the RESET function during reset and following reset.
Port C
Bit 7
653321
Bit 0
MCU Pin:
PTC7/
SS1
PTC6/
SPSCK1
PTC5/
MISO1
PTC4/
MOSI1
PTC3/
KBI2P3
PTC2/
KBI2P2
PTC1/
KBI2P1
PTC0/
KBI2P0
Port D
Bit 7
6
54321
Bit 0
MCU Pin:
PTD6/
TPM1CH0
PTD5
PTD4
PTD3
PTD2
PTD1/
RESET
PTD0/
BKGD/MS