MC68HC908GP32_08 Datasheet, PDF (122/266 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Input/Output (I/O) Ports
12.4 Port C
Port C is a 7-bit, general-purpose bidirectional I/O port. Port C also has software configurable pullup
devices if configured as an input port.
12.4.1 Port C Data Register
The port C data register (PTC) contains a data latch for each of the seven port C pins.
NOTE
Bit 6 and bit 5 of PTC are not available in a 40-pin dual in-line package and
42-pin shrink dual in-line package.
Address: $0002
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
Write:
PTC6
PTC5
PTC4
PTC3
PTC2
PTC1
PTC0
Reset:
Unaffected by reset
= Unimplemented
Figure 12-9. Port C Data Register (PTC)
PTC6–PTC0 — Port C Data Bits
These read/write bits are software-programmable. Data direction of each port C pin is under the control
of the corresponding bit in data direction register C. Reset has no effect on port C data.
12.4.2 Data Direction Register C
Data direction register C (DDRC) determines whether each port C pin is an input or an output. Writing a
logic 1 to a DDRC bit enables the output buffer for the corresponding port C pin; a logic 0 disables the
output buffer.
Address: $0006
Bit 7
6
5
4
3
2
1
Bit 0
Read: 0
Write:
DDRC6 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1 DDRC0
Reset: 0
0
0
0
0
0
0
0
= Unimplemented
Figure 12-10. Data Direction Register C (DDRC)
DDRC6–DDRC0 — Data Direction Register C Bits
These read/write bits control port C data direction. Reset clears DDRC6–DDRC0, configuring all port
C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
NOTE
Avoid glitches on port C pins by writing to the port C data register before
changing data direction register C bits from 0 to 1.
MC68HC908GP32 Data Sheet, Rev. 10
122
Freescale Semiconductor