MC9S08DZ60 Datasheet, PDF (158/396 Pages) Freescale Semiconductor, Inc – Microcontrollers

Multi-Purpose Clock Generator (S08MCGV1)
In this particular case, the MCU has been attached to a PCB and the entire assembly is undergoing final
test with automated test equipment. A separate signal or message is provided to the MCU operating under
user provided software control. The MCU initiates a trim procedure as outlined in Figure 8-12 while the
tester supplies a precision reference signal.
If the intended bus frequency is near the maximum allowed for the device, it is recommended to trim using
a reference divider value (RDIV setting) of twice the final value. After the trim procedure is complete, the
reference divider can be restored. This will prevent accidental overshoot of the maximum clock frequency.
MC9S08DZ60 Series Data Sheet, Rev. 1 Draft E
158
PRELIMINARY
Freescale Semiconductor
Subject to Change