Input/Output (I/O) Ports (PORTS)
Port C
10.4 Port C
Port C is a 7-bit, general-purpose, bidirectional I/O port that shares two of its pins
with the analog-to-digital convertor module (ADC).
10.4.1 Port C Data Register
The port C data register (PTC) contains a data latch for each of the seven port C
pins.
Address:
$0002
Bit 7
0
6
5
4
3
2
1
Bit 0
Read:
Write:
Reset:
PTC6
PTC5
PTC4
PTC3
PTC2
PTC1
PTC0
R
Unaffected by reset
R
= Reserved
Figure 10-8. Port C Data Register (PTC)
PTC[6:0] — 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.
10.4.2 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
0
6
5
DDRC5
0
4
DDRC4
0
3
DDRC3
0
2
DDRC2
0
1
DDRC1
0
Bit 0
DDRC0
0
Read:
Write:
Reset:
DDRC6
R
0
0
R
= Reserved
Figure 10-9. Data Direction Register C (DDRC)
DDRC[6:0] — Data Direction Register C Bits
These read/write bits control port C data direction. Reset clears DDRC[6:0],
configuring all port C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
MOTOROLA Input/Output (I/O) Ports (PORTS)
Data Sheet
117
FREESCALE [ Freescale ]
