Controlling Clock; Example Of Setting High-Speed On-Chip Oscillator - Renesas RL78/G1P Hardware User Manual

RL78/G1P

5.6 Controlling Clock

5.6.1 Example of setting high-speed on-chip oscillator

After a reset release, the CPU/peripheral hardware clock (f
oscillator clock. The frequency of the high-speed on-chip oscillator can be selected from 32, 24, 16, 12, 8, 6, 4, 3, 2, and 1
MHz by using FRQSEL0 to FRQSEL3 of the option byte (000C2H).
[Option byte setting]
Address: 000C2H
7
Option
byte
CMODE1
(000C2H)
0/1
CMODE1
1
1
Other than above
FRQSEL3
1
0
1
0
1
0
1
0
1
1
[High-speed on-chip oscillator frequency select register (HOCODIV) setting]
Address: F00A8H
7
0
HOCODIV
HOCODIV2 HOCODIV1 HOCODIV0
0
0
0
0
1
1
R01UH0895EJ0100 Rev.1.00
Nov 29, 2019
6 5
CMODE0
0/1 1
CMODE0
0
LS (low speed main) mode
1 HS (high speed main) mode
Setting prohibited
FRQSEL2 FRQSEL1
0 0
0 0
0 0
0 0
0 1
0 1
0 1
0 1
1 0
1 0
Other than above
6 5
0 0
0 0
0 1
1 0
1 1
0 0
0 1
Other than above
CHAPTER 5 CLOCK GENERATOR
) always starts operating with the high-speed on-chip
CLK
4 3
FRQSEL3 FRQSEL2
0 0/1
Setting of flash operation mode
V = 2.7 V to 3.6 V @ 1 MHz to 8 MHz
DD
V = 2.7 V to 3.6 V @ 1 MHz to 32 MHz
DD
FRQSEL0 Frequency of the high-speed on-chip oscillator
0
32 MHz
0 24 MHz
1 16 MHz
1
12 MHz
0 8 MHz
0 6 MHz
1
4 MHz
1
3 MHz
0 2 MHz
1 1 MHz
Setting prohibited
4 3
0 0 HOCODIV2 HOCODIV1 HOCODIV0
Selection of high-speed on-chip oscillator clock frequency
FRQSEL3 Bit is 0
24 MHz
12 MHz
6 MHz
3 MHz
Setting prohibited
Setting prohibited
Setting prohibited
2 1 0
FRQSEL1 FRQSEL0
0/1 0/1 0/1
2 1 0
FRQSEL3 Bit is 1
32 MHz
16 MHz
8 MHz
4 MHz
2 MHz
1 MHz
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