MC68HC908GT16 Datasheet, PDF (235/412 Pages) Motorola, Inc – Microcontrollers

Input/Output (I/O) Ports
Port B
When bit DDRBx is a logic 1, reading address $0001 reads the PTBx
data latch. When bit DDRBx is a logic 0, reading address $0001 reads
the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit. Table 16-3 summarizes
the operation of the port B pins.
Table 16-3. Port B Pin Functions
DDRB PTB
Bit Bit
I/O Pin
Mode
Accesses
to DDRB
Read/Write
Accesses
to PTB
Read
Write
0
X⁽¹⁾ Input, Hi-Z^{(2) DDRB7–DDRB0}
Pin
PTB7–PTB0⁽³⁾
1
X
Output
DDRB7–DDRB0 PTB7–PTB0 PTB7–PTB0
1. X = Don’t care
2. Hi-Z = High impedance
3. Writing affects data register, but does not affect input.
MC68HC908GT16 • MC68HC908GT8 — Rev. 2
MOTOROLA
Input/Output (I/O) Ports
Technical Data
235