s908az32ag2cfue Freescale Semiconductor, Inc, s908az32ag2cfue Datasheet - Page 256

• Manufacturer Part Number: s908az32ag2cfue
• Description: M68hc08 Microcontrollers 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

I/O Ports
23.7.2 Data Direction Register F
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[6:0] — Data Direction Register F Bits
Figure 23-19
256
These read/write bits control port F data direction. Reset clears DDRF[6:0], configuring all port F pins
as inputs.
1 = Corresponding port F pin configured as output
0 = Corresponding port F pin configured as input
shows the port F I/O logic.
Address:
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.
Reset:
Read:
Write:
READ DDRF ($000D)
WRITE DDRF ($000D)
WRITE PTF ($0009)
READ PTF ($0009)
$000D
Bit 7
R
R
0
0
Figure 23-18. Data Direction Register F (DDRF)
= Reserved
DDRF6
6
0
RESET
MC68HC908AZ32A Data Sheet, Rev. 2
Figure 23-19. Port F I/O Circuit
DDRF5
5
0
NOTE
DDRF4
DDRFx
PTFx
4
0
DDRF3
3
0
DDRF2
2
0
DDRF1
1
0
Freescale Semiconductor
DDRF0
Bit 0
PTFx
0