Motorola MC68HC908MR32 사용자 설명서
Advance Information
MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
320
Input/Output (I/O) Ports
MOTOROLA
Input/Output (I/O) Ports
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].
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.
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.
15.8.2 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.
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
These read/write bits control port F data direction. Reset clears
DDRF[5:0], configuring all port F pins as inputs.
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
0 = Corresponding port F pin configured as input
NOTE:
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.
changing data direction register F bits from 0 to 1.
Address:
$000D
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
DDRF5
DDRF4
DDRF3
DDRF2
DDRF1
DDRF0
Write:
R
R
Read:
0
0
0
0
0
0
R
= Reserved
Figure 15-17. Data Direction Register F (DDRF)