mc68hc908mr32 Freescale Semiconductor, Inc, mc68hc908mr32 Datasheet - Page 110

• Manufacturer Part Number: mc68hc908mr32
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports (PORTS)
10.7 Port F
Port F is a 6-bit, special function port that shares four of its pins with the serial peripheral interface module
(SPI) and two pins with the serial communications interface (SCI).
10.7.1 Port F Data Register
The port F data register (PTF) contains a data latch for each of the six port F pins.
PTF[5:0] — Port F Data Bits
10.7.2 Data Direction Register F
Data direction register F (DDRF) 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
110
These read/write bits are software programmable. Data direction of each port F pin is under the control
of the corresponding bit in data direction register F. Reset has no effect on PTF[5:0].
These read/write bits control port F data direction. Reset clears DDRF[5:0], configuring all port F pins
as inputs.
1 = Corresponding port F pin configured as output
0 = Corresponding port F pin configured as input
Address:
Address:
Reset:
Data direction register F (DDRF) does not affect the data direction of port F
pins that are being used by the SPI or SCI module. However, the DDRF bits
always determine whether reading port F returns the states of the latches
or the states of the pins.
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.
Read:
Read:
Read:
Write:
Write:
$000D
$0009
Bit 7
Bit 7
R
R
R
R
0
0
Figure 10-17. Data Direction Register F (DDRF)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
= Reserved
= Reserved
Figure 10-16. Port F Data Register (PTF)
6
0
R
6
0
R
DDRF5
PTF5
5
5
0
DDRF4
Unaffected by reset
NOTE
NOTE
PTF4
4
4
0
DDRF3
PTF3
3
3
0
DDRF2
PTF2
2
2
0
DDRF1
PTF1
1
1
0
Freescale Semiconductor
DDRF0
PTF0
Bit 0
Bit 0
0