MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 296

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

I/O Ports
Data Direction
Register E
MC68HC708XL36
296
NOTE:
Address: $000C
Data direction register E 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.
DDRE[7:0] — Data Direction Register E Bits
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
Reset:
Read:
Write:
These read/write bits control port E data direction. Reset clears
DDRE[7:0], configuring all port E pins as inputs.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
DDR37
Bit 7
0
shows the port E I/O logic.
Figure 15. Data Direction Register E (DDRE)
READ DDRE ($000C)
WRITE DDRE ($000C)
WRITE PORTE ($0008)
READ PORTE ($0008)
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DDRE6
6
0
I/O Ports
Figure 16. Port E I/O Circuit
DDRE5
RESET
5
0
DDRE4
4
0
DDREx
PEx
DDRE3
3
0
DDRE2
2
0
DDTE1
1
0
MOTOROLA
14-ports_a
DDRE0
Bit 0
0
PEx