MC68HC908GP32 Datasheet, PDF (234/410 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Freescale Semiconductor, Inc.
Input/Output (I/O) Ports
16.7.2 Data Direction Register E
Data direction register E (DDRE) determines whether each port E pin is
an input or an output. Writing a logic 1 to a DDRE bit enables the output
buffer for the corresponding port E pin; a logic 0 disables the output
buffer.
Address: $000C
Bit 7
6
5
4
3
2
1
Read: 0
0
0
0
0
0
DDRE1
Write:
Reset: 0
0
0
0
0
0
0
= Unimplemented
Figure 16-18. Data Direction Register E (DDRE)
Bit 0
DDRE0
0
DDRE1 and DDRE0 — Data Direction Register E Bits
These read/write bits control port E data direction. Reset clears
DDRE1 and DDRE0, configuring all port E pins as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
NOTE: Avoid glitches on port E pins by writing to the port E data register before
changing data direction register E bits from 0 to 1.
Figure 16-19 shows the port E I/O logic.
Technical Data
232
MC68HC908GP32•MC68HC08GP32 — Rev. 6
Input/Output (I/O) Ports
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