MC68HC08JK1 Datasheet, PDF (75/198 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
System Integration Module (SIM)
Exception Control
7.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter. (See 7.7.2 Stop Mode
for details.) The SIM counter is free-running after all reset states. (See
7.4.2 Active Resets from Internal Sources for counter control and
internal reset recovery sequences.)
7.6 Exception Control
Normal, sequential program execution can be changed in three different
ways:
• Interrupts
– Maskable hardware CPU interrupts
– Non-maskable software interrupt instruction (SWI)
• Reset
• Break interrupts
7.6.1 Interrupts
An interrupt temporarily changes the sequence of program execution to
respond to a particular event. Figure 7-8 flow charts the handling of
system interrupts.
Interrupts are latched, and arbitration is performed in the SIM at the start
of interrupt processing. The arbitration result is a constant that the CPU
uses to determine which vector to fetch. Once an interrupt is latched by
the SIM, no other interrupt can take precedence, regardless of priority,
until the latched interrupt is serviced (or the I bit is cleared).
MC68H(R)C08JL3 — Rev. 4
MOTOROLA
System Integration Module (SIM)
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Technical Data
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