MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 262

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Input/Output Ports
DDRF[6:0] — Data Direction Register F Bits
Figure 22-19
When bit DDRFx is a logic 1, reading address $0009 reads the PTFx data latch. When bit DDRFx is a
logic 0, reading address $0009 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
262
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
X = don’t care
Hi-Z = high impedance
1. Writing affects data register, but does not affect input.
shows the port F I/O logic.
DDRF
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.
Bit
0
1
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
READ DDRF ($000D)
WRITE DDRF ($000D)
WRITE PTF ($0009)
READ PTF ($0009)
PTF
Bit
X
X
Table 22-6. Port F Pin Functions
RESET
Figure 22-19. Port F I/O Circuit
Input, Hi-Z
I/O Pin
Output
Mode
Table 22-6
NOTE
Accesses to DDRF
DDRFx
PTFx
Read/Write
DDRF[6:0]
DDRF[6:0]
summarizes the operation of the port F pins.
PTF[6:0]
Read
Pin
Accesses to PTF
PTF[6:0]
Freescale Semiconductor
PTF[6:0]
Write
PTFx
(1)