MC68HC12 MOTOROLA [Motorola, Inc], MC68HC12 Datasheet - Page 59

• 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]

3.5.5 Port J
3.5.6 Port K
MC68HC912DT128A — Rev 4.0
MOTOROLA
Setting the RDPH bit in register RDRIV causes all port H outputs to have
reduced drive level. RDRIV can be written once after reset. RDRIV is not
in the address map in peripheral mode. Refer to
Input/Output.
Port J pins are used for key wake-ups that can be used with the pins
configured as inputs or outputs. The key wake-ups are triggered with
either a rising or falling edge signal (KWPJ). An interrupt is generated if
the corresponding bit is enabled (KWIEJ). If any of the interrupts is not
enabled, the corresponding pin can be used as a general purpose I/O
pin. Refer to
Register DDRJ determines whether each port J pin is an input or output.
Setting a bit in DDRJ makes the corresponding bit in port J an output;
clearing a bit in DDRJ makes the corresponding bit in port J an input. The
default reset state of DDRJ is all zeroes.
Register KWPJ not only determines what type of edge the key wake ups
are triggered, but it also determines what type of resistive load is used
for port J input pins when PUPJ bit is set in the PUCR register. Setting a
bit in KWPJ makes the corresponding key wake up input pin trigger at
rising edges and loads a pull down in the corresponding port J input pin.
Clearing a bit in KWPJ makes the corresponding key wake up input pin
trigger at falling edges and loads a pull up in the corresponding port J
input pin. The default state of KWPJ is all zeroes.
Setting the RDPJ bit in register RDRIV causes all port J outputs to have
reduced drive level. RDRIV can be written once after reset. RDRIV is not
in the address map in peripheral mode. Refer to
Input/Output.
Port K pins are used for page index emulation in expanded or peripheral
modes. When page index emulation is not enabled, EMK is not set in
MODE register, or the part is in single chip mode, these pins can be used
Pinout and Signal Descriptions
I/O Ports with Key
Wake-up.
Pinout and Signal Descriptions
Bus Control and
Bus Control and
Technical Data
Port Signals
59