CHAPTER 5 CLOCK GENERATOR
Preliminary User’s Manual U16315EJ1V0UD
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5.8.4 Switching from subsystem clock to X1 input clock
Figure 5-17. Switching from Subsystem Clock to X1 Input Clock (Flowchart)
; Subsystem clock operation
; X1 oscillating?
; X1 oscillation enabled
; Wait for X1 oscillation stabilization time
; X1 input clock operation
CLS is changed from 1 to 0.
MCS = 1 not changed.
X1 oscillation stabilization time elapsed
X1 oscillation
stabilization time
not elapsed
Yes: X1 oscillation stopped
No: X1 oscillating
MCC
←
0
PCC.4 (CSS) = 1
MCM = 03H
MCC = 1?
OSTC check
CSS
←
0
X1 input clock operation
Subsystem
clock operation
X1 input
clock operation