upd78f0124m6gba1-8et Renesas Electronics Corporation., upd78f0124m6gba1-8et Datasheet - Page 128

• Manufacturer Part Number: upd78f0124m6gba1-8et
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.8.4 Switching from subsystem clock to X1 input clock
128
clock operation
clock operation
Subsystem
X1 input
Figure 5-17. Switching from Subsystem Clock to X1 Input Clock (Flowchart)
No: X1 oscillating
X1 oscillation
stabilization time
not elapsed
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16315EJ3V1UD
X1 input clock operation
PCC.4 (CSS) = 1
OSTC check
MCM = 03H
MCC = 1?
MCC ← 0
CSS ← 0
X1 oscillation stabilization time elapsed
Yes: X1 oscillation stopped
; Subsystem clock operation
CLS is changed from 1 to 0.
MCS = 1 not changed.
; X1 oscillating?
; X1 oscillation enabled
; Wait for X1 oscillation stabilization time
; X1 input clock operation