MC9S12HZ256 Datasheet, PDF (40/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 1 MC9S12HZ256 Device Overview
1.5.6.5 PE6 / MODB / IPIPE1 — Port E I/O Pin 6
PE6 is a general-purpose input or output pin. It is used as a MCU operating mode select pin during reset.
The state of this pin is latched to the MODB bit at the rising edge of RESET. This pin is shared with the
instruction queue tracking signal IPIPE1. This pin is an input with a pull-down device which is only active
when RESET is low.
1.5.6.6 PE5 / MODA / IPIPE0 — Port E I/O Pin 5
PE5 is a general-purpose input or output pin. It is used as a MCU operating mode select pin during reset.
The state of this pin is latched to the MODA bit at the rising edge of RESET. This pin is shared with the
instruction queue tracking signal IPIPE0. This pin is an input with a pull-down device which is only active
when RESET is low.
1.5.6.7 PE4 / ECLK — Port E I/O Pin 4
PE4 is a general-purpose input or output pin. It can be configured to drive the internal bus clock ECLK.
ECLK can be used as a timing reference.
1.5.6.8 PE3 / FP21 / LSTRB / TAGLO — Port E I/O Pin 3
PE3 is a general-purpose input or output pin. It can be configured as frontplane segment driver output FP21
of the LCD module. In MCU expanded modes of operation, LSTRB is used for the low-byte strobe
function to indicate the type of bus access and when instruction tagging is on, TAGLO is used to tag the
low half of the instruction word being read into the instruction queue.
1.5.6.9 PE2 / FP20 / R/W — Port E I/O Pin 2
PE2 is a general-purpose input or output pin. It can be configured as frontplane segment driver output FP20
of the LCD module. In MCU expanded modes of operations, this pin performs the read/write output signal
for the external bus. It indicates the direction of data on the external bus.
1.5.6.10 PE1 / IRQ — Port E Input Pin 1
PE1 is a general-purpose input pin and also the maskable interrupt request input that provides a means of
applying asynchronous interrupt requests. If IRQ is enabled, this pin can wake up the MCU from stop or
wait mode.
1.5.6.11 PE0 / XIRQ — Port E Input Pin 0
PE0 is a general-purpose input pin and also the non-maskable interrupt request input that provides a means
of applying asynchronous interrupt requests. This can wake up the MCU from stop or wait mode.
MC9S12HZ256 Data Sheet, Rev. 2.04
40
Freescale Semiconductor