MC68HC08AZ0 Datasheet, PDF (335/444 Pages) Motorola, Inc – Advance Information

Freescale Semiconductor, Inc.
I/O Ports
Port B
When bit DDRBx is a logic one, reading address $0001 reads the PTBx
data latch. When bit DDRBx is a logic zero, 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 3 summarizes the
operation of the port B pins.
Table 3. Port B pin functions
DDRB Bit
0
PTB Bit
X⁽¹⁾
I/O Pin Mode
Input, Hi-Z⁽²⁾
Accesses to
DDRB
Read/Write
DDRB[7:0]
1
X
Output
DDRB[7:0]
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect input.
Accesses to PTB
Read
Pin
PTB[7:0]
Write
PTB[7:0]⁽³⁾
PTB[7:0]
7-io
MOTOROLA
I/O Ports
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MC68HC08AZ0
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