MC68HC08JB1 Datasheet, PDF (85/216 Pages) Motorola, Inc – Microcontrollers

8.5.1 SIM Counter During Power-On Reset
The power-on reset module (POR) detects power applied to the MCU.
At power-on, the POR circuit asserts the signal PORRST. Once the SIM
is initialized, it enables the oscillator to drive the bus clock state machine.
8.5.2 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 or reset, the SIM
senses the state of the short stop recovery bit, SSREC, in the
configuration register (CONFIG). If the SSREC bit is a logic 1, then the
stop recovery is reduced from the normal delay of 4096 OSCXCLK
cycles down to 2048 OSCXCLK cycles. This is ideal for applications
using canned oscillators that do not require long startup times from stop
mode. External crystal applications should use the full stop recovery
time, that is, with SSREC cleared in the configuration register (CONFIG).
8.5.3 SIM Counter and Reset States
External reset has no effect on the SIM counter. (See 8.7.2 Stop Mode
for details.) The SIM counter is free-running after all reset states. (See
8.4.2 Active Resets from Internal Sources for counter control and
internal reset recovery sequences.)
8.6 Exception Control
Normal, sequential program execution can be changed in two different
ways:
• Interrupts
– Maskable hardware CPU interrupts
– Non-maskable software interrupt instruction (SWI)
• Reset
MC68HC08JB1 — Rev. 2.1
Freescale Semiconductor
Technical Data
85