upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 117

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

5.8 Clock Switching Flowchart and Register Setting
5.8.1 Switching from internal oscillation clock to high-speed system clock
Internal oscillation
High-speed system
Note Check the oscillation stabilization wait time of the high-speed system clock oscillator after reset release
clock operation
clock operation
Register value
after reset
Figure 5-14. Switching from internal oscillation Clock to High-Speed System Clock (Flowchart)
using the OSTC register and then switch to the high-speed system clock operation after the oscillation
stabilization wait time has elapsed. The OSTS register setting is valid only after STOP mode is released by
interrupt during high-speed system clock operation.
High-speed system clock
(dividing set PCC)
Internal oscillation
clock operation
oscillation stabilization
time has not elapsed
High-speed system clock operation
CHAPTER 5 CLOCK GENERATOR
User’s Manual U16962EJ3V0UD
Each processing
OSTS = 05H
OSTC check
OSTC = 00H
MCM = 00H
RCM = 00H
MOC = 00H
PCC setting
MCM.0 ← 1
PCC = 00H
After reset
High-speed system clock oscillation stabilization time has elapsed
Note
Note
; f
; Internal oscillator oscillation
; Internal oscillation clock operation
; High-speed system clock oscillation
; Oscillation stabilization time status register
; Oscillation stabilization time f
CPU
; High-speed system clock oscillation
stabilization time status check
MCM.1 (MCS) is changed from 0 to 1
= f
R
XP
/2
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