MC68HC05RC17 Datasheet, PDF (44/128 Pages) Freescale Semiconductor, Inc – General Release Specification

Interrupts
Freescale Semiconductor, Inc.
When edge sensitivity is selected for the IRQ interrupt, it is sensitive to
these cases:
1. Falling edge on the IRQ pin
2. Falling edge on any port B pin with pullup/interrupt enabled
When edge and level sensitivity is selected for the IRQ interrupt, it is
sensitive to these cases:
1. Low level on the IRQ pin
2. Falling edge on the IRQ pin
3. Falling edge or low level on any port B pin with pullup/interrupt
enabled
External interrupts also can be masked by setting the EIMSK bit in the
MSCR register of the IR remote timer. See 9.5.4 Modulator Period
Data Registers for details.
4.8 External Interrupt Timing
If the interrupt mask bit (I bit) of the CCR is set, all maskable interrupts
(internal and external) are disabled. Clearing the I bit enables interrupts.
The interrupt request is latched immediately following the falling edge of
the IRQ source. It is then synchronized internally and serviced as
specified by the contents of $3FFA and $3FFB.
Either a level-sensitive and edge-sensitive trigger or an edge-sensitive-
only trigger is available via the mask programmable option for the IRQ
pin.
4.9 Carrier Modulator Transmitter Interrupt (CMT)
A CMT interrupt occurs when the end-of-cycle flag (EOC) and the end-
of-cycle interrupt enable (EOCIE) bits are set in the modulator control
and status register (MCSR). This interrupt will vector to the interrupt
service routine located at the address specified by the contents of
memory locations $3FF8 and $3FF9.
General Release Specification
MC68HC05RC17 — Rev. 2.0
Interrupts
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