RL78/G13 CHAPTER 5 CLOCK GENERATOR
R01UH0146EJ0100 Rev.1.00 300
Sep 22, 2011
(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/0102CH) can be changed
by using high-speed on-chip oscillator frequency select register (HOCODIV). However, the selectable frequency
depends on the FRQSEL3 bit of the option byte (000C2H/0102CH).
The HOCODIV register can be set by an 8-bit memory manipulation instruction.
Reset signal generation clears this register to default value (undefined).
Figure 5-9. Format of High-speed On-chip Oscillator Frequency Select Register (HOCODIV)
Address: F00A8H After reset: undefined R/W
Symbol 7 6 5 4 3 2 1 0
HOCODIV
0 0 0 0 0
HOCODIV2 HOCODIV1 HOCODIV0
High-Speed On-Chip Oscillator Clock Frequency
HOCODIV2 HOCODIV1 HOCODIV0
FRQSEL3 Bit is 0 FRQSEL3 Bit of is 1
0 0 0 24 MHz 32 MHz
0 0 1 12 MHz 16 MHz
0 1 0 6 MHz 8 MHz
0 1 1 3 MHz 4 MHz
1 0 0 Setting prohibited 2 MHz
1 0 1 Setting prohibited 1 MHz
Other than aboves Setting prohibited
Cautions 1. Set the HOCODIV register within the operable voltage range both before and after
changing the frequency.
2. Use the device within the voltage of the flash operation mode set by the option
byte (000C2H/010C2H) even after the frequency has been changed by using the
HOCODIV register.
Option Byte
(000C2H/010C2H) Value
CMODE1 CMODE2
Flash Operation Mode
Operating
Frequency Range
Operating Voltage
Range
0 0 LV (low-voltage main) mode 1 to 4 MHz 1.6 to 5.5 V
1 0 LS (low-speed main) mode 1 to 8 MHz 1.8 to 5.5 V
1 to 16 MHz 2.4 to 5.5 V 1 1 HS (high-speed main) mode
1 to 32 MHz 2.7 to 5.5 V
3. When setting of high-speed on-chip oscillator clock as system clock, the device
operates at the old frequency for the duration of 3 clocks after the frequency value
has been changed by using the HOCODIV register.
4. To change the frequency of the high-speed on-chip oscillator when X1 oscillation,
external oscillation input or subclock is set for the system clock, stop the high-
speed on-chip oscillator by setting bit 0 (HIOSTOP) of the CSC register to 1 and
then change the frequency.
<R>
<R>
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