Multipurpose Clock Generator (MCG)
MCF51CN128 Reference Manual, Rev. 6
Freescale Semiconductor
6-25
Figure 6-10. Flowchart of PEE to BLPI Mode Transition using an 8 MHz crystal
MCGC1 = 0x98
CHECK
CLKST = %10 ?
MCGC2 = 0x3E
MCGC1 = 0x5C
CHECK
IREFST = 0?
CHECK
CLKST = %01?
CONTINUE
IN BLPI MODE
START
IN PEE MODE
MCGC3 = 0x18
ENTER
BLPE MODE ?
IN
BLPE MODE ?
(LP=1)
MCGC2 = 0x36
(LP = 0)
CHECK
PLLST = 0?
OPTIONAL:
= 1?
MCGC2 = 0x08
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
CHECK LOCK
(LP = 1)