mc68hc908lj24 Freescale Semiconductor, Inc, mc68hc908lj24 Datasheet - Page 395

• Manufacturer Part Number: mc68hc908lj24
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

18.7.2 Data Direction Register E (DDRE)
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor
NOTE:
Address:
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.
the port E I/O logic.
Reset:
Read:
Write:
These read/write bits control port E data direction. Reset clears
DDRE[7:0], configuring all port E pins as inputs.
1 = Corresponding port E pin configured as output
0 = Corresponding port E pin configured as input
DDRE7
READ DDRE ($0009)
WRITE DDRE ($0009)
WRITE PTE ($0008)
READ PTE ($0008)
$0009
Bit 7
Figure 18-17. Data Direction Register E (DDRE)
0
Input/Output (I/O) Ports
DDRE6
6
0
Figure 18-18. Port E I/O Circuit
RESET
DDRE5
5
0
DDRE4
DDREx
PTEx
4
0
DDRE3
3
0
DDRE2
Figure 18-18
2
0
Input/Output (I/O) Ports
DDRE1
1
0
Data Sheet
shows
DDRE0
Bit 0
Port E
0
PTEx
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