MC68HC705J1AC 查看數據表（PDF） - Freescale Semiconductor

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MC68HC705J1AC

Microcontrollers

Freescale Semiconductor 

General Description

IRQ/VPP

1.7 IRQ/VPP

The external interrupt/programming voltage pin (IRQ/VPP) drives the

asynchronous IRQ interrupt function of the CPU. Additionally, it is used

to program the user EPROM and mask option register. (See Section 2.

Memory and Section 8. External Interrupt Module (IRQ).)

The LEVEL bit in the mask option register provides negative

edge-sensitive triggering or both negative edge-sensitive and low

level-sensitive triggering for the interrupt function.

NOTE:

If level-sensitive triggering is selected, the IRQ/VPP input requires an

external resistor to VDD for wired-OR operation. If the IRQ/VPP pin is not

used, it must be tied to the VDD supply.

The IRQ/VPP pin contains an internal Schmitt trigger as part of its input

to improve noise immunity. The voltage on this pin should not exceed

VDD except when the pin is being used for programming the EPROM.

The mask option register can enable the PA0–PA3 pins to function as

external interrupt pins.

1.8 PA0–PA7

These eight input/output (I/O) lines comprise port A, a general-purpose,

bidirectional I/O port. See Section 8. External Interrupt Module (IRQ)

for information on PA0–PA3 external interrupts.

1.9 PB0–PB5

These six I/O lines comprise port B, a general-purpose, bidirectional I/O

port.

MC68HC705J1A — Rev. 4.0

MOTOROLA

General Description

Technical Data

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