MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 299

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Data Direction
Register F
17-ports_a
MOTOROLA
NOTE:
Address: $000D
Data direction register F determines whether each port F pin is an input
or an output. Writing a logic 1 to a DDRF bit enables the output buffer for
the corresponding port F pin; a logic 0 disables the output buffer.
DDRF[5:0] — Data Direction Register F Bits
Avoid glitches on port F pins by writing to the port F data register before
changing data direction register F bits from 0 to 1.
Figure 19
Reset:
Read:
Write:
These read/write bits control port F data direction. Reset clears
DDRF[5:0], configuring all port F pins as inputs.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Corresponding port F pin configured as output
0 = Corresponding port F pin configured as input
Bit 7
0
shows the port F I/O logic.
Figure 18. Data Direction Register F (DDRF)
READ DDRF ($000D)
WRITE DDRF ($000D)
WRITE PORTF ($0009)
READ PORTF ($0009)
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= Unimplemented
6
0
I/O Ports
Figure 19. Port F I/O Circuit
DDRF5
RESET
5
0
DDRF4
4
0
DDRFx
PFx
DDRF3
3
0
DDRF2
2
0
MC68HC708XL36
DDRF1
1
0
I/O Ports
DDRF0
Bit 0
Port F
0
299
PFx