MC68HC708XL36 FREESCALE [Freescale Semiconductor, Inc], MC68HC708XL36 Datasheet - Page 318

• Manufacturer Part Number: MC68HC708XL36
• Description: HCMOS Microcontroller Unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

IRQ
IRQ Module During Break Interrupts
IRQ Status and Control Register
MC68HC708XL36
318
Address:
The BCFE bit in the break flag control register (BFCR) enables software
to clear CPU interrupt requests during the break state. (See Break
Module on page 149.)
To allow software to clear IRQ1 and IRQ2 CPU interrupt requests during
a break interrupt, write a logic 1 to the BCFE bit. If a CPU interrupt
request is cleared during the break state, it remains cleared when the
MCU exits the break state.
To protect CPU interrupt flags during the break state, write a logic 0 to
the BCFE bit. With BCFE at logic 0 (its default state), writing to the ACK1
and ACK2 bits in the IRQ status and control register during the break
state has no effect on the IRQ interrupt flags.
The IRQ status and control register (ISCR) controls and monitors
operation of the IRQ module. The ISCR has the following functions:
Reset:
Read:
Write:
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Freescale Semiconductor, Inc.
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Shows the state of the IRQ1 and IRQ2 interrupt flags
Clears IRQ1 and IRQ2 CPU interrupt flags
Masks IRQ1 and IRQ2 CPU interrupt requests
Controls triggering sensitivity of the IRQ1 and IRQ2 CPU interrupt
pins
IRQF2
$0032
Figure 2. IRQ Status and Control Register (ISCR)
Bit 7
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= Unimplemented
ACK2
6
0
IRQ
IMASK2
5
MODE2
4
IRQF1
3
ACK1
2
0
IMASK1
1
MOTOROLA
8-intirq2_a
MODE1
Bit 0