mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 271

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

The sequence for clock quality check is shown in
1. A Clock Monitor Reset will always set the SCME bit to logical’1’
Freescale Semiconductor
POR
check window
Clock OK
or clock monitor reset
check the OSCCLK signal.
The clock quality checker enables the PLL and the voltage regulator
(VREG) anytime a clock check has to be performed. An ongoing clock
quality check could also cause a running PLL (f
during pseudo-stop mode or wait mode
LVR
Remember that in parallel to additional actions caused by self-clock mode
osc ok
num=0
active?
SCM
?
yes
no
exit full stop
no
yes
Figure 9-20. Sequence for Clock Quality Check
CM fail
Switch to OSCCLK
1
handling the clock quality checker continues to
num=num+1
Exit SCM
num<50
?
MC9S12Q128
yes
Rev 1.09
NOTE
NOTE
Clock Monitor Reset
Enter SCM
Figure
Chapter 9 Clocks and Reset Generator (CRGV4) Block Description
no
9-20.
yes
SCM
) and an active VREG
SCME=1
active?
SCM
?
no
yes
no
num=50
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