MC68HC08AZ32A Datasheet, PDF (159/312 Pages) Motorola, Inc – HCMOS Microcontroller Unit

13.4 Port C
Port C is a 6-bit general-purpose bidirectional I/O port.
Port C
13.4.1 Port C Data Register (PTC)
The port C data register contains a data latch for each of the six port C pins.
Address: $0002
Bit 7
6
5
4
3
2
Read: 0
Write:
0
PTC5
PTC4
PTC3
PTC2
Reset:
Unaffected by reset
Alternative Functions:
MCLK
= Unimplemented
Figure 13-8. Port C Data Register (PTC)
1
PTC1
Bit 0
PTC0
PTC[5:0] — 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.
MCLK — System Clock Bit
The system clock is driven out of PTC2 when enabled by MCLKEN in PTC DDR7.
13.4.2 Data Direction Register C (DDRC)
Data direction register C determines whether each port C pin is an input or an output. Writing a 1 to a
DDRC bit enables the output buffer for the corresponding port C pin; a 0 disables the output buffer.
Address: $0006
Bit 7
6
5
Read:
0
MCLKEN
Write:
DDRC5
Reset: 0
0
0
= Unimplemented
4
DDRC4
0
3
DDRC3
0
2
DDRC2
0
1
DDRC1
0
Bit 0
DDRC0
0
Figure 13-9. Data Direction Register C (DDRC)
MCLKEN — MCLK Enable Bit
This read/write bit enables MCLK to be an output signal on PTC2. If MCLK is enabled, DDRC2 has no
effect. Reset clears this bit.
1 = MCLK output enabled
0 = MCLK output disabled
MC68HC08AZ32A Data Sheet, Rev. 2
Freescale Semiconductor
159