Datasheet

Internal Clock Generator (S08ICGV2)
MC9S08GB60A Data Sheet, Rev. 2
122 Freescale Semiconductor
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.
RECOVERY FROM
CONTINUE
CHECK
LOCK = 1?
NO
YES
FLL LOCK STATUS.
INITIALIZE ICG
ICG1 = $28
ICG2 = $31
RECOVERY
CONTINUE
CHECK
LOCK = 1?
NO
YES
FLL LOCK STATUS.
NOTE: THIS WILL REQUIRE THE INTERAL REFERENCE CLOCK TO START AND
STABILIZE.
FROM STOP3
RESET, STOP1, STOP2