MC68HC08AS32 Datasheet, PDF (200/394 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Input/Output (I/O) Ports
READ DDRE ($000C)
WRITE DDRE ($000C)
RESET
WRITE PTE ($0008)
DDREx
PTEx
PTEx
READ PTE ($0008)
Figure 15-15. Port E I/O Circuit
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. Table 15-6 summarizes
the operation of the port E pins.
Table 15-6. Port E Pin Functions
DDRE
Bit
0
PTE
I/O Pin
Accesses
to DDRE
Accesses to PTE
Bit
Mode
Read/Write
Read
Write
X
Input, Hi-Z DDRE[7:0]
Pin
PTE[7:0]⁽¹⁾
1
X
Output
DDRE[7:0] PTE[7:0]
PTE[7:0]
X = Don’t Care
Hi-Z = High Impedance
1. Writing affects data register, but does not affect input.
Advance Information
200
Input/Output (I/O) Ports
MC68HC08AS32 — Rev. 3.0
MOTOROLA