CHAPTER 6 CLOCK GENERATOR
Page 115 of 920
6.3.8
High-speed on-chip oscillator frequency select register (HOCODIV)
The frequency of the high-speed on-chip oscillator which is set by an option byte (000C2H) can be changed by
using high-speed on-chip oscillator frequency select register (HOCODIV).
The HOCODIV register can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to the value set by FRQSEL2 to FRQSEL0 of the option byte
(000C2H).
Figure 6 - 12 Format of High-speed on-chip oscillator frequency select register (HOCODIV)
Caution 1. Set the HOCODIV register within the operable voltage range of the flash operation mode set in the
option byte (000C2H) before and after the frequency change.
Caution 2. Set the HOCODIV register with the high-speed on-chip oscillator clock (f
IH
) selected as the
CPU/peripheral hardware clock (f
CLK
).
Caution 3. After the frequency is changed with the HOCODIV register, the frequency is switched after the
following transition time has elapsed.
• Operation for up to three clocks at the pre-change frequency
• CPU/peripheral hardware clock wait at the post-change frequency for up to three clocks
Address: F00A8H
After reset: the value set by FRQSEL2 to FRQSEL0 of the option byte (000C2H)
Symbol
7
6
5
4
3
2
1
0
0
0
0
0
0
HOCODIV2
HOCODIV1
HOCODIV0
Selection of high-speed on-chip oscillator clock frequency
FRQSEL3 = 0
FRQSEL3 = 1
0
0
0
f
IH
= 24 MHz
f
IH
= 32 MHz
0
0
1
f
IH
= 12 MHz
f
IH
= 16 MHz
0
1
0
f
IH
= 6 MHz
f
IH
= 8 MHz
0
1
1
f
IH
= 3 MHz
f
IH
= 4 MHz
1
0
0
Setting prohibited
f
IH
= 2 MHz
1
0
1
Setting prohibited
f
IH
= 1 MHz
Other than above
Setting prohibited
Value of option byte (000C2H)
Flash operation mode
Operating frequency range
Operating voltage range
CMODE0
0
LS (low-speed main) mode
1 MHz to 8 MHz
1.8 V to 3.6 V
1
HS (high-speed main) mode
1 MHz to 16 MHz
2.4 V to 3.6 V
1 MHz to 32 MHz
2.7 V to 3.6 V
Summary of Contents for RL78/G1H
Page 941: ...R01UH0575EJ0120 RL78 G1H...
