MC68HC912DG128 Datasheet, PDF (100/452 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Bus Control and Input/Output
Bit 7
6
5
4
3
2
1
Bit 0
DDE7
DDE6
DDE5
DDE4
DDE3
DDE2
0
0
RESET:
0
0
0
0
0
0
0
0
DDRE — Port E Data Direction Register
$0009
This register determines the primary direction for each port E pin
configured as general-purpose I/O.
0 = Associated pin is a high-impedance input
1 = Associated pin is an output
PE[1:0] are associated with XIRQ and IRQ and cannot be configured as
outputs. These pins can be read regardless of whether the alternate
interrupt functions are enabled.
This register is not in the map in peripheral mode and expanded modes
while the EME control bit is set.
Read and write anytime.
RESET:
BIT 7
NDBE
0
6
CGMTE
0
5
PIPOE
0
4
NECLK
0
3
LSTRE
0
2
RDWE
0
RESET:
0
0
1
0
1
1
RESET:
1
1
0
1
0
0
RESET:
1
0
0
1
0
0
RESET:
0
0
1
0
1
1
PEAR — Port E Assignment Register
1
CALE
0
0
0
0
0
BIT 0
DBENE
0
Normal
Expanded
0
Special
Expanded
0
Peripheral
0
Normal
single chip
0
Special
single chip
$000A
The PEAR register is used to choose between the general-purpose I/O
functions and the alternate bus control functions of Port E. When an
Technical Data
100
MC68HC912DG128 — Rev 3.0
Bus Control and Input/Output
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