Interrupts

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 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 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 (MDR1, MDR2, and MDR3) 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

 

MC68HC05RC16 — Rev. 3.0

 

 

 

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Interrupts

MOTOROLA