NEC V850ES/F 3-L Series User Manual page 175

Clock Generator
subclock to main
Caution
1. Setting the MCK bit to "0": Enables main clock oscillation.
2. Software wait: Insert wait status via program to wait until the oscillation
stabilization time of the main clock oscillator (OSTC.MSTS = 1) is elapsed.
3. Setting the CK3 bit to "0": Set via a bit manipulation instruction. Do not
change the CK2 to CK0 bits.
Main clock operation: The maximum time required for switching to the main
clock operation which is specified by the CK2 to CK0 bits after the CK3 bit
is set, is as follows.
• When OB7B.SUBCLK = 0: 1 / Subclock oscillation frequency (fXT)
• When OB7B.SUBCLK = 1: 1 / low-speed internal oscillation frequency
(fRL)
Read the CLS bit and confirm that the operation has been switched to the
main clock operation.
Do not change to a different clock selection until the previous one has entered
a stable status.
User's Manual U18743EE1V2UM00
Chapter 4
175