System Integration Module (SIM)
Exception Control
MC68HC908AB32
—
Rev. 1.0
Technical Data
MOTOROLA
System Integration Module (SIM)
123
8.6.2 Reset
All reset sources always have equal and highest priority and cannot be
arbitrated.
8.6.3 Break Interrupts
The break module can stop normal program flow at a software-
programmable break point by asserting its break interrupt output. See
Section 22. Break Module (BRK)
. The SIM puts the 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 each module is affected by the
break state.
8.6.4 Status Flag Protection in Break Mode
The SIM controls whether status flags contained in other modules can
be cleared during break mode. The user can select whether flags are
protected from being cleared by properly initializing the break clear flag
enable bit (BCFE) in the SIM break flag control register (SBFCR).
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 normal.
Содержание MC68HC908AB32
Страница 1: ...MC68HC908AB32 D REV 1 0 MC68HC908AB32 HCMOS Microcontroller Unit TECHNICAL DATA ...
Страница 2: ......
Страница 68: ...FLASH Memory Technical Data MC68HC908AB32 Rev 1 0 68 FLASH Memory MOTOROLA ...
Страница 84: ...EEPROM Technical Data MC68HC908AB32 Rev 1 0 84 EEPROM MOTOROLA ...
Страница 108: ...Central Processor Unit CPU Technical Data MC68HC908AB32 Rev 1 0 108 Central Processor Unit CPU MOTOROLA ...
Страница 130: ...System Integration Module SIM Technical Data MC68HC908AB32 Rev 1 0 130 System Integration Module SIM MOTOROLA ...
Страница 338: ...Input Output I O Ports Technical Data MC68HC908AB32 Rev 1 0 338 Input Output I O Ports MOTOROLA ...
Страница 364: ...Low Voltage Inhibit LVI Technical Data MC68HC908AB32 Rev 1 0 364 Low Voltage Inhibit LVI MOTOROLA ...
Страница 386: ...Electrical Specifications Technical Data MC68HC908AB32 Rev 1 0 386 Electrical Specifications MOTOROLA ...
Страница 390: ...Ordering Information Technical Data MC68HC908AB32 Rev 1 0 390 Ordering Information MOTOROLA ...
Страница 391: ......