MC68HC908QT2CDW Freescale Semiconductor, MC68HC908QT2CDW Datasheet - Page 73

• Manufacturer Part Number: MC68HC908QT2CDW
• Description: IC MCU 1.5K FLASH W/ADC 8-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908QT2CDW

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LVD, POR, PWM
• Number Of I /o: 5
• Program Memory Size: 1.5KB (1.5K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-SOIC (5.3mm Width), 8-SOP, 8-SOEIAJ
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -

Chapter 8
External Interrupt (IRQ)
8.1 Introduction
The IRQ pin (external interrupt), shared with PTA2 (general purpose input) and keyboard interrupt (KBI),
provides a maskable interrupt input
8.2 Features
Features of the IRQ module include the following:
8.3 Functional Description
IRQ pin functionality is enabled by setting configuration register 2 (CONFIG2) IRQEN bit accordingly. A
zero disables the IRQ function and PTA2 will assume the other shared functionalities. A one enables the
IRQ function.
A low level applied to the external interrupt request (IRQ) pin can latch a CPU interrupt request.
Figure 8-2
Interrupt signals on the IRQ pin are latched into the IRQ latch. The IRQ latch remains set until one of the
following actions occurs:
The external interrupt pin is falling-edge-triggered out of reset and is software-configurable to be either
falling-edge or falling-edge and low-level triggered. The MODE bit in INTSCR controls the triggering
sensitivity of the IRQ pin.
Freescale Semiconductor
•
•
•
•
•
•
•
•
External interrupt pin, IRQ
IRQ interrupt control bits
Programmable edge-only or edge and level interrupt sensitivity
Automatic interrupt acknowledge
Selectable internal pullup resistor
IRQ vector fetch — An IRQ vector fetch automatically generates an interrupt acknowledge signal
that clears the IRQ latch.
Software clear — Software can clear the IRQ latch by writing a 1 to the ACK bit in the interrupt
status and control register (INTSCR).
Reset — A reset automatically clears the IRQ latch.
shows the structure of the IRQ module.
MC68HC908QY/QT Family Data Sheet, Rev. 6
73