mc68hc912dg128 Freescale Semiconductor, Inc, mc68hc912dg128 Datasheet - Page 99

• Manufacturer Part Number: mc68hc912dg128
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

PORTE — Port E Register
MC68HC912DG128 — Rev 3.0
MOTOROLA
Function
RESET:
Alt. Pin
ECLK or
DBE or
BIT 7
CAL
PE7
—
IPIPE1 or
CGMTST
MODB or
PE6
—
6
This register is associated with external bus control signals and interrupt
inputs, including data bus enable (DBE), 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 pull-ups (DBE, LSTRB,
R/W, IRQ, and XIRQ). A single control bit enables the pull-ups for all
these pins which are configured as inputs.
This register is not in the map in peripheral mode or expanded modes
when the EME bit is set.
Read and write anytime.
Freescale Semiconductor, Inc.
For More Information On This Product,
MODA or
IPIPE0
PE5
—
5
Bus Control and Input/Output
Go to: www.freescale.com
ECLK
PE4
—
4
LSTRB or
TAGLO
PE3
—
3
PE2
R/W
—
2
PE1
IRQ
—
Bus Control and Input/Output
1
XIRQ
BIT 0
PE0
—
Technical Data
Registers
$0008
99