MC68HC812A4 Datasheet, PDF (102/342 Pages) Motorola, Inc – 16-bit device composed of standard on-chip peripheral modules connected by an intermodule bus. Modules include

Bus Control and Input/Output (I/O)
6.4.9 Port E Data Register
Address: $0008
Bit 7
6
5
4
3
2
Read:
PE7
PE6
PE5
PE4
PE3
PE2
Write:
Reset:
Unaffected by reset
Normal narrow expanded: 0
0
0
0
1
0
All other modes: 0
0
0
0
0
0
Alternate pin function: ARST
MODB or MODA or
IPIPE1 IPIPE0
ECLK
LSTRB
R/W
Figure 6-9. Port E Data Register (PORTE)
1
Bit 0
PE1
PE0
0
0
0
0
IRQ
XIRQ
Read: Anytime, if register is in the map
Write: Anytime, if register is in the map
This register is associated with external bus control signals and interrupt
inputs including auxiliary reset (ARST), mode select (MODB/IPIPE1,
MODA/IPIPE0), E-clock, size (LSTRB), read/write (R/W), IRQ, and
XIRQ. When the associated pin is not used for one of these specific
functions, the pin can be used as general-purpose I/O. The port E
assignment register (PEAR) selects the function of each pin. DDRE
determines the primary direction of each port E pin when configured to
be general-purpose I/O.
Some of these pins have software selectable pullups (LSTRB, R/W, and
XIRQ). A single control bit enables the pullups for all these pins which
are configured as inputs. IRQ always has a pullup.
PE7 can be selected as a high-true auxiliary reset input.
This register is not in the map in peripheral mode or expanded modes
when the EME bit is set.
MC68HC812A4 — Rev. 3.0
102
Bus Control and Input/Output (I/O)
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