mc68hc05jp6pe Freescale Semiconductor, Inc, mc68hc05jp6pe Datasheet - Page 51

• Manufacturer Part Number: mc68hc05jp6pe
• Description: M68hc05 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

MC68HC05JJ6/MC68HC05JP6
Freescale Semiconductor
IRQ
PA0
PA3
PA2
PA1
EDGE- AND LEVEL
MASK OPTION
MASK OPTION
(ENABLE = 1)
INTERRUPT
(ENABLE=1)
KEYBOARD
EDGE- OR
With the edge- and level-sensitive trigger option, a falling edge or a low
level on the IRQ pin latches an external interrupt request. The edge- and
level-sensitive trigger mask option allows connection to the IRQ pin of
multiple wired-OR interrupt sources. As long as any source is holding the
IRQ low, an external interrupt request is present, and the CPU continues
to execute the interrupt service routine.
With the edge-sensitive-only trigger mask option, a falling edge on the
IRQ pin latches an external interrupt request. A subsequent interrupt
request can be latched only after the voltage level on the IRQ pin returns
to a logic one and then falls again to logic zero.
—
Figure 4-3. External Interrupt Logic
Rev. 3.2
IRQ VECTOR FETCH
INTERNAL DATA BUS
Interrupts
RST
V
DD
LATCH
IRQ
R
IRQ STATUS/CONTROL REGISTER ($000D)
General Release Specification
TO BIH & BIL
INSTRUCTION
PROCESSING
EXTERNAL
INTERRUPT
REQUEST
Interrupts
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