MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 254

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Input/Output Ports
22.4 Port C
Port C is an 6-bit general-purpose bidirectional I/O port. Note that PTC5 is only available on 64-pin
package options.
22.4.1 Port C Data Register
The port C data register contains a data latch for each of the six port C pins.
PTC[5:0] — Port C Data Bits
MCLK — System Clock Bit
22.4.2 Data Direction Register C
Data direction register C 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.
MCLKEN — MCLK Enable Bit
254
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 (5:0).
The system clock is driven out of PTC2 when enabled by MCLKEN bit in PTCDDR7.
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
Alternative
Functions:
Address:
Address:
Reset:
Reset:
Read:
Read:
Write:
Write:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
MCLKEN
$0002
$0006
Bit 7
Bit 7
R
R
R
0
0
Figure 22-9. Data Direction Register C (DDRC)
= Reserved
= Reserved
Figure 22-8. Port C Data Register (PTC)
R
R
6
0
6
0
0
DDRC5
PTC5
5
5
0
DDRC4
Unaffected by Reset
PTC4
4
4
0
DDRC3
PTC3
3
3
0
DDRC2
MCLK
PTC2
2
2
0
DDRC1
PTC1
1
1
0
Freescale Semiconductor
DDRC0
PTC0
Bit 0
Bit 0
0