M68HC08 datasheet(97/288 Pages) FREESCALE

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System Integration Module (SIM)

MC68HC908BD48 — Rev. 2.1

Data Sheet

Freescale Semiconductor

System Integration Module (SIM)

7.5.2 SIM Counter During Stop Mode Recovery

The SIM counter also is used for stop mode recovery. The STOP

instruction clears the SIM counter. After an interrupt, break, or reset, the

SIM senses the state of the short stop recovery bit, SSREC, in the

configure register 1 (CONFIG1). If the SSREC bit is a logic one, then the

stop recovery is reduced from the normal delay of 4096 OSCXCLK

cycles down to 32 OSCXCLK cycles. This is ideal for applications using

canned oscillators that do not require long start-up times from stop

mode. External crystal applications should use the full stop recovery

time, that is, with SSREC cleared.

7.5.3 SIM Counter and Reset States

External reset has no effect on the SIM counter (see 7.7.2 Stop Mode).

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

Normally, sequential program execution can be changed in three

different ways:

•

Interrupts

–

Maskable hardware CPU interrupts

–

Non-maskable software interrupt instruction (SWI)

•

Reset

•

Break interrupts

M68HC08 数据表(PDF) 97 Page - Freescale Semiconductor, Inc