mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 312

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
20.6.2 Data Direction Register D
Technical Data
NOTE:
NOTE:
NOTE:
Address:
Data direction register D (DDRD) does not affect the data direction of
port D pins that are being used by the ADC. However, the DDRD bits
always determine whether reading port D returns the states of the
latches or logic 0.
TACLK — Timer Clock Input Bit
Do not use ADC channel ATD14 when using the PTD6/TACLK pin as the
clock input for the TIMA.
Data direction register D (DDRD) 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[7:0] — 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.
Reset:
Read:
Write:
The PTD6/TACLK pin is the external clock input for the TIMA. The
prescaler select bits, PS[2:0], select PTD6/TACLK as the TIMA clock
input. (See
selected as the TIMA clock, PTD6/TACLK is available for
general-purpose I/O or as an ADC channel.
These read/write bits control port D data direction. Reset clears
DDRD[7:0], configuring all port D pins as inputs.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Corresponding port D pin configured as output
0 = Corresponding port D pin configured as input
DDRD7
$0007
Bit 7
Figure 20-12. Data Direction Register D (DDRD)
0
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Input/Output (I/O) Ports
22.9.1 TIMA Status and Control
DDRD6
6
0
DDRD5
5
0
DDRD4
4
0
DDRD3
3
0
MC68HC908AS60 — Rev. 1.0
Register.) When not
DDRD2
2
0
DDRD1
1
0
DDRD0
Bit 0
0