mc68hc908jb16 Freescale Semiconductor, Inc, mc68hc908jb16 Datasheet - Page 273

• Manufacturer Part Number: mc68hc908jb16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

14.5.2 Data Direction Register D
MC68HC908JB16
Freescale Semiconductor
NOTE:
NOTE:
—
Rev. 1.1
Address:
Data direction register D determines whether each port D pin is an input
or an output. Writing a logic 1 to a DDRD bit enables the output buffer for
the corresponding port D pin; a logic 0 disables the output buffer.
DDRD[5:0] — Data Direction Register D Bits
Avoid glitches on port D pins by writing to the port D data register before
changing data direction register D bits from 0 to 1.
For those devices packaged in a 32-pin low-profile quad flat pack,
PTD5–1 are not connected. DDRD5–1 should be set to a 1 to configure
PTD5–1 as outputs.
Figure 14-10
Reset:
Read:
Write:
These read/write bits control port D data direction. Reset clears
DDRD[5:0], configuring all port D pins as inputs.
Port D pins are open-drain when configured as output.
1 = Corresponding port D pin configured as output
0 = Corresponding port D pin configured as input
$0007
Bit 7
0
0
Figure 14-9. Data Direction Register D (DDRD)
shows the port D I/O circuit logic.
Input/Output (I/O) Ports
6
0
0
DDRD5
5
0
DDRD4
4
0
DDRD3
3
0
DDRD2
2
0
Input/Output (I/O) Ports
DDRD1
1
0
Technical Data
DDRD0
Bit 0
0
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