MC68HC708MP16 Datasheet, PDF (332/398 Pages) Freescale Semiconductor, Inc – Microcontrollers

Input/Output (I/O) Ports
READ DDRF ($000B)
WRITE DDRF ($000B)
RESET
DDRFx
WRITE PTF ($0005)
PTFx
PTFx
READ PTF ($0005)
Figure 15-18. Port F I/O Circuit
When bit DDRFx is a logic 1, reading address $0005 reads the PTFx
data latch. When bit DDRFx is a logic 0, reading address $0005 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit. Table 15-3 summarizes
the operation of the port F pins.
Table 15-6. Port F Pin Functions
DDRF PTF
Bit
Bit
I/O Pin Mode
0
X⁽¹⁾
Input, Hi-Z⁽²⁾
Accesses to
DDRF
Read/Write
DDRF[6:0]
1
X
Output
DDRF[6:0]
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect input.
Accesses to PTF
Read
Pin
PTF[6:0]
Write
PTF[6:0]⁽³⁾
PTF[6:0]
Technical Data
332
Input/Output (I/O) Ports
MC68HC708MP16 — Rev. 3.1
Freescale Semiconductor