Freescale Semiconductor MC68HC08KH12 - Manual (Page 217)

MC68HC(7)08KH12 — Rev. 1.1 Advance Information
Freescale Semiconductor 217
14.5 IRQ Module During Break Interrupts
The system integration module (SIM) controls whether the IRQ1 latch
can be cleared during the break state. The BCFE bit in the break flag
control register (BFCR) enables software to clear the latches during the
break state.
(See Section 7. System Integration Module (SIM) .)
To allow software to clear the IRQ1 latch during a break interrupt, write
a logic one to the BCFE bit. If a latch is cleared during the break state, it
remains cleared when the MCU exits the break state.
To protect the latches during the break state, write a logic zero to the
BCFE bit. With BCFE at logic zero (its default state), writing to the ACK1
bit in the IRQ status and control register during the break state has no
effect on the IRQ latch.
14.6 IRQ Status and Control Register (ISCR)
The IRQ Status and Control Register (ISCR) controls and monitors
operation of the IRQ module. The ISCR has the following functions:
• Shows the state of the IRQ1 flag
• Clears the IRQ1 latch
• Masks IRQ1 and interrupt request
• Controls triggering sensitivity of the IRQ1/V
PP
interrupt pin
Address: $001E
Bit 7 6 5 4 3 2 1 Bit 0
Read: 0 0 0 0 IRQF1 0
IMASK1 MODE1
Write: ACK1
Reset: 0 0 0 0 0 0 0 0
= Unimplemented
Figure 14-2. IRQ Status and Control Register (ISCR)