MC912D60ACPVE8 Datasheet, PDF (54/460 Pages) Freescale Semiconductor, Inc – MC68HC912D60A MC68HC912D60C MC68HC912D60P Technical Data

Pinout and Signal Descriptions
When the PUPB bit in the PUCR register is set, all port B input pins are
pulled-up internally by an active pull-up device. This bit has no effect if
the port is being used in expanded modes as the pull-ups are inactive.
Setting the RDPB bit in register RDRIV causes all port B 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 Bus Control and
Input/Output.
3.6.3 Port E
Port E pins operate differently from port A and B pins. Port E pins are
used for bus control signals and interrupt service request signals. When
a pin is not used for one of these specific functions, it can be used as
general-purpose I/O. However, two of the pins (PE[1:0]) can only be
used for input, and the states of these pins can be read in the port data
register even when they are used for IRQ and XIRQ.
The PEAR register determines pin function, and register DDRE
determines whether each pin is an input or output when it is used for
general-purpose I/O. PEAR settings override DDRE settings. Because
PE[1:0] are input-only pins, only DDRE[7:2] have effect. Setting a bit in
the DDRE register makes the corresponding bit in port E an output;
clearing a bit in the DDRE register makes the corresponding bit in port E
an input. The default reset state of DDRE is all zeros.
When the PUPE bit in the PUCR register is set, PE7 and PE[3:0] are
pulled up by active devices.
Neither port E nor DDRE is in the map in peripheral mode; neither is in
the internal map in expanded modes with EME set.
Setting the RDPE bit in register RDRIV causes all port E 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 Bus Control and
Input/Output.
Technical Data
54
Pinout and Signal Descriptions
MC68HC912D60A — Rev. 3.1
Freescale Semiconductor