Freescale Semiconductor MPC5553 - Page 447

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
11-32 Freescale Semiconductor
Figure 11-12. FM Auto-Calibration Flow Chart
Count M Reference Clock Cycles.
CALX = Value in Feedback Counter
Allow System 3*384 Reference
Counts to Settle
CAL[N] = 1
Enable FM. N = 7
Count M Reference Clock Cycles.
Store Value of Feedback
Counter in CAL0
Enter Calibration Mode;
Set PCALPASS = 1
Let DIFF = CALX-CAL0
DIFF > 0
?
Yes
Let ERR = DIFF-EXP
ERR > 0
?
No
A
CAL[N] = 0
Yes
PCALPASS = 0
No
A
N = 0
?
No
Yes
N = N-1
CALDONE = 1
DONE
For MFD = 0 to 2: M = 960
For MFD = 3 to 5: M = 640
For MFD = 6 to 8: M = 480
For MFD = 9 to 14: M = 320
For MFD = 15 to 20: M = 240
For MFD = 21 to 31: M = 160