UPD78F0138 NEC, UPD78F0138 Datasheet - Page 142

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

5.8.4 Switching from subsystem clock to X1 input clock
142
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 U16228EJ2V0UD
X1 input clock operation
PCC.4 (CSS) = 1
OSTC check
MCM = 03H
MCC = 1?
MCC
CSS
X1 oscillation stabilization time elapsed
Yes: X1 oscillation stopped
0
0
; 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