MC68HC12 MOTOROLA [Motorola, Inc], MC68HC12 Datasheet - Page 107

• Manufacturer Part Number: MC68HC12
• Description: The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit
• Manufacturer: MOTOROLA [Motorola, Inc]

DDRE — Port E Data Direction Register
MC68HC912DT128A — Rev 4.0
MOTOROLA
RESET:
DDE7
Bit 7
0
DDE6
6
0
(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.
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.
0 = Associated pin is a high-impedance input
1 = Associated pin is an output
DDE5
5
0
Bus Control and Input/Output
DDE4
4
0
DDE3
3
0
DDE2
2
0
Bus Control and Input/Output
1
0
0
Bit 0
0
0
Technical Data
Registers
$0009
107