Motorola MC68HC908MR32 用户手册
Input/Output (I/O) Ports
Port F
MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
Advance Information
MOTOROLA
Input/Output (I/O) Ports
319
When bit DDREx is a logic 1, reading address $0008 reads the PTEx
data latch. When bit DDREx is a logic 0, reading address $0008 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
data latch. When bit DDREx is a logic 0, reading address $0008 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
summarizes
the operation of the port E pins.
15.8 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).
serial peripheral interface module (SPI) and two pins with the serial
communications interface (SCI).
15.8.1 Port F Data Register
The port F data register (PTF) contains a data latch for each of the six
port F pins.
port F pins.
Table 15-5. Port E Pin Functions
DDRE
Bit
PTE
Bit
I/O Pin Mode
Accesses
to DDRE
Accesses to PTE
Read/Write
Read
Write
0
X
(1)
1. X = don’t care
Input, Hi-Z
(2)
2. Hi-Z = high impedance
DDRE[7:0]
Pin
PTE[7:0]
(3)
3. Writing affects data register, but does not affect input.
1
X
Output
DDRE[7:0]
PTE[7:0]
PTE[7:0]
Address:
$0009
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
PTF5
PTF4
PTF3
PTF2
PTF1
PTF0
Write:
R
R
Reset:
Unaffected by reset
R
= Reserved
Figure 15-16. Port F Data Register (PTF)