MC68HC908JB8 Datasheet, PDF (208/286 Pages) Motorola, Inc – MICROCONTROLLERS

Input/Output Ports (I/O)
12.5.2 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.
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 12-9. 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.
NOTE:
For those devices packaged in a 20-pin PDIP, 20-pin SOIC, and 28-pin
SOIC package, PTC7–PTC1 are not connected. DDRC7–DDRC1
should be set to a 1 to configure PTC7–PTC1 as outputs.
Figure 12-10 shows the port C I/O logic.
Technical Data
208
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
Input/Output Ports (I/O)
Freescale Semiconductor