mc68hc912d60c Freescale Semiconductor, Inc, mc68hc912d60c Datasheet - Page 89

• Manufacturer Part Number: mc68hc912d60c
• Description: Hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

PORTE — Port E Register
DDRE — Port E Data Direction Register
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor
RESET:
Function
RESET:
Alt. Pin
ECLK or
DDE7
DBE or
Bit 7
BIT 7
PE7
CAL
0
—
IPIPE1 or
CGMTST
MODB or
DDE6
PE6
6
0
—
6
This register is associated with external bus control signals and interrupt
inputs, including data bus enable (DBE), mode select (MODB/IPIPE1,
MODA/IPIPE0), ECLK, 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.
This register determines the primary direction for each port E pin
configured as general-purpose I/O.
MODA or
DDE5
IPIPE0
PE5
5
0
—
5
Bus Control and Input/Output
DDE4
ECLK
PE4
—
4
0
4
BDTAGL or
LSTRB or
TAGLO
DDE3
PE3
—
3
0
3
DDE2
PE2
R/W
—
2
0
2
PE1
IRQ
—
1
0
0
Bus Control and Input/Output
1
XIRQ
BIT 0
Bit 0
PE0
—
0
0
Technical Data
Registers
$0008
$0009
89