UPD78F0138 NEC, UPD78F0138 Datasheet - Page 140

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

5.8.2 Switching from X1 input clock to Ring-OSC clock
140
Note Required only when “clock can be stopped by software” is selected for Ring-OSC by a mask option.
clock operation
clock operation
Ring-OSC
X1 input
Figure 5-15. Switching from X1 Input Clock to Ring-OSC Clock (Flowchart)
Register setting
clock operation
in X1 input
RSTOP = 0
Yes: RSTOP = 1
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16228EJ2V0UD
Ring-OSC clock operation
PCC.7 (MCC) = 0
PCC.4 (CSS) = 0
(RSTOP) = 1?
MCM = 03H
MCM0
RCM.0
No: RSTOP = 0
Note
0
; X1 oscillation
; X1 input clock or Ring-OSC clock
; X1 input clock operation
; Ring-OSC oscillating?
; Ring-OSC oscillating
MCM.1 (MCS) is changed from 1 to 0