MC68HC908LJ24 Datasheet, PDF (388/464 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Input/Output (I/O) Ports
18.5.2 Data Direction Register C (DDRC)
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.
Address: $0006
Bit 7
6
5
4
3
2
1
Read:
DDRC7 DDRC6 DDRC5 DDRC4 DDRC3 DDRC2 DDRC1
Write:
Reset: 0
0
0
0
0
0
0
Figure 18-10. Data Direction Register C (DDRC)
Bit 0
DDRC0
0
DDRC[7:0] — Data Direction Register C Bits
These read/write bits control port C data direction. Reset clears
DDRC[7:0], configuring all port C pins as inputs.
1 = Corresponding port C pin configured as output
0 = Corresponding port C pin configured as input
NOTE:
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. Figure 18-11 shows
the port C I/O logic.
READ DDRC ($0006)
WRITE DDRC ($0006)
RESET
WRITE PTC ($0002)
READ PTC ($0002)
DDRCx
PTCx
PTCx
Figure 18-11. Port C I/O Circuit
Data Sheet
388
MC68HC908LJ24/LK24 — Rev. 2
Input/Output (I/O) Ports
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA