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.
Address:
$0009
Bit 7
0
6
0
5
4
3
2
1
Bit 0
Read:
Write:
Reset:
PTF5
PTF4
PTF3
PTF2
PTF1
PTF0
R
R
Unaffected by reset
R
= Reserved
Figure 10-16. Port F Data Register (PTF)
PTF[5:0] — Port F Data Bits
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].
NOTE:
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.
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.
Address:
$000D
Bit 7
0
6
0
5
DDRF5
0
4
DDRF4
0
3
DDRF3
0
2
DDRF2
0
1
DDRF1
0
Bit 0
DDRF0
0
Read:
Write:
Read:
R
R
R
= Reserved
Figure 10-17. Data Direction Register F (DDRF)
DDRF[5:0] — Data Direction Register F Bits
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
Data Sheet
122
MC68HC908MR32 • MC68HC908MR16 — Rev. 6.0
Input/Output (I/O) Ports (PORTS)
MOTOROLA
FREESCALE [ Freescale ]
