mc68hc908mr32 Freescale Semiconductor, Inc, mc68hc908mr32 Datasheet - Page 106

• Manufacturer Part Number: mc68hc908mr32
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports (PORTS)
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.
PTC[6:0] — Port C Data Bits
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.
DDRC[6:0] — Data Direction Register C Bits
106
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.
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
Address:
Address:
Reset:
Reset:
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.
Read:
Read:
Write:
Write:
$0002
$0006
Bit 7
Bit 7
R
R
R
R
0
0
0
Figure 10-9. Data Direction Register C (DDRC)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
= Reserved
= Reserved
Figure 10-8. Port C Data Register (PTC)
DDRC6
PTC6
6
6
0
DDRC5
PTC5
5
5
0
DDRC4
Unaffected by reset
NOTE
PTC4
4
4
0
DDRC3
PTC3
3
3
0
DDRC2
PTC2
2
2
0
DDRC1
PTC1
1
1
0
Freescale Semiconductor
DDRC0
PTC0
Bit 0
Bit 0
0