MC68HC708AS48 FREESCALE [Freescale Semiconductor, Inc], MC68HC708AS48 Datasheet - Page 140

• Manufacturer Part Number: MC68HC708AS48
• Description: Advance Information
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

System Integration Module (SIM)
9.6.2 Reset
9.6.3 Break Interrupts
9.6.4 Status Flag Protection in Break Mode
Advance Information
140
All reset sources always have higher priority than interrupts and cannot
be arbitrated.
The break module can stop normal program flow at a
software-programmable break point by asserting its break interrupt
output. (See
CPU into the break state by forcing it to the SWI vector location. Refer
to the break interrupt subsection of each module to see how the break
state affects each module.
The SIM controls whether status flags contained in other modules can
be cleared during break mode. The user can select to protect flags from
being cleared by properly initializing the break clear flag enable bit
(BCFE) in the SIM break flag control register (SBFCR). (See
Break Flag Control
Protecting flags in break mode ensures that set flags will not be cleared
while in break mode. This protection allows registers to be freely read
and written during break mode without losing status flag information.
Setting the BCFE bit enables the clearing mechanisms. Once cleared in
break mode, a flag remains cleared even when break mode is exited.
Status flags with a two-step clearing mechanism — for example, a read
of one register followed by the read or write of another — are protected,
even when the first step is accomplished prior to entering break mode.
Upon leaving break mode, execution of the second step will clear the
flag as usual.
System Integration Module (SIM)
Section 11. Break Module
Register.)
(Break).) The SIM puts the
MC68HC708AS48
MOTOROLA
9.8.3 SIM
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Rev. 4.0