Switching From Subsystem Clock To X1 Input Clock; Switching From Subsystem Clock To X1 Input Clock (Flowchart) - NEC 78K0 User Manual

6.8.4

Switching from subsystem clock to X1 input clock

Figure 6-17. Switching from Subsystem Clock to X1 Input Clock (Flowchart)
Subsystem
clock operation
X1 input
clock operation
166
CHAPTER 6 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
User's Manual U15947EJ2V0UD
; 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.