Switching From Subsystem Clock To X1 Input Clock - NEC 78K0/KD1 Series User Manual

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