MC68HC908GZ16 Datasheet, PDF (164/314 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
13.4 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.
13.4.1 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 through bit 2 of PTC are not available in the 32-pin LQFP package.
Address:
Read:
Write:
Reset:
Alternative
Function:
$0002
Bit 7
1
6
PTC6
5
PTC5
4
3
PTC4
PTC3
Unaffected by reset
2
PTC2
1
PTC1
Bit 0
PTC0
CAN_RX CAN_TX
= Unimplemented
Figure 13-9. 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.
CAN_RX and CAN_TX — MSCAN08 Bits
The CAN_RX–CAN_TX pins are the MSCAN08 modules receive and transmit pins. The CANEN bit in the
MSCAN08 control register determines, whether the PTC1/CAN_RX–PTC0/CAN_TX pins are MSCAN08
pins or general-purpose I/O pins. See Chapter 12 MSCAN08 Controller (MSCAN08).
13.4.2 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:
Read:
Write:
Reset:
$0006
Bit 7
0
6
DDRC6
5
DDRC5
4
DDRC4
3
DDRC3
2
DDRC2
1
DDRC1
0
0
0
0
0
0
0
= Unimplemented
Figure 13-10. Data Direction Register C (DDRC)
Bit 0
DDRC0
0
MC68HC908GZ16 • MC68HC908GZ8 Data Sheet, Rev. 1
164
Freescale Semiconductor