upd70f3017ay Renesas Electronics Corporation., upd70f3017ay Datasheet - Page 141

• Manufacturer Part Number: upd70f3017ay
• Description: V850/sa1tm 32-/16-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

(a) Example of main clock operation → subclock operation setup
(b) Example of subclock operation → main clock operation setup
<1> CK2 ← 1:
<2> Subclock operation:
<3> MCK ← 1:
<1> MCK ← 0:
<2> Insert a wait using a program and wait until the main clock oscillation stabilization time elapses.
<3> CK2 ← 0:
<4> Main clock operation: At least two instructions are required before main clock operation after the CK2
CHAPTER 6 CLOCK GENERATION FUNCTION
Bit manipulation instructions are recommended. Do not change CK1 and CK0.
The maximum number of the following instructions is required before subclock
operation after the CK2 bit is set.
(CPU clock frequency before setting/subclock frequency) × 2
Therefore, insert the wait described above using a program.
Only when the main clock is stopped.
Main clock oscillation start
Bit manipulation instructions are recommended. Do not change CK1 and CK0.
bit is set.
User’s Manual U12768EJ4V1UD
141