MC9S08GB60A Datasheet, PDF (122/302 Pages) Freescale Semiconductor, Inc – HCS08 Microcontrollers

Internal Clock Generator (S08ICGV2)
RECOVERY FROM
RESET, STOP1, STOP2
RECOVERY
FROM STOP3
INITIALIZE ICG
ICG1 = $28
ICG2 = $31
CHECK
FLL LOCK STATUS. ^NO
LOCK = 1?
YES
CHECK
NO
FLL LOCK STATUS.
LOCK = 1?
YES
CONTINUE
CONTINUE
NOTE: THIS WILL REQUIRE THE INTERAL REFERENCE CLOCK TO START AND
STABILIZE.
Figure 7-10. ICG Initialization and Stop Recovery for Example #3
7.4.5 Example #4: Internal Clock Generator Trim
The internally generated clock source is guaranteed to have a period ± 25% of the nominal value. In some
case this may be sufficient accuracy. For other applications that require a tight frequency tolerance, a
trimming procedure is provided that will allow a very accurate source. This section outlines one example
of trimming the internal oscillator. Many other possible trimming procedures are valid and can be used.
MC9S08GB60A Data Sheet, Rev. 2
122
Freescale Semiconductor