R5F212B7SNFP#U0 Renesas Electronics America, R5F212B7SNFP#U0 Datasheet - Page 126

• Manufacturer Part Number: R5F212B7SNFP#U0
• Description: IC R8C/2B MCU FLASH 64-LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/2Br

Specifications of R5F212B7SNFP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: POR, PWM, Voltage Detect, WDT
• Number Of I /o: 55
• Program Memory Size: 48KB (48K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.5K x 8
• Voltage - Supply (vcc/vdd): 2.2 V ~ 5.5 V
• Data Converters: A/D 12x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 64-LQFP
• For Use With: R0K5212D8S001BE - KIT STARTER FOR R8C/2DR0K5212D8S000BE - KIT DEV FOR R8C/2D
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/2A Group, R8C/2B Group
Rev.2.00
REJ09B0324-0200
10.2
10.2.1
10.2.2
These clocks are supplied by the on-chip oscillators (high-speed on-chip oscillator and a low-speed on-chip
oscillator). The on-chip oscillator clock is selected by the FRA01 bit in the FRA0 register.
The clock generated by the low-speed on-chip oscillator is used as the clock source for the CPU clock,
peripheral function clock, fOCO, and fOCO-S.
After reset, the on-chip oscillator clock generated by the low-speed on-chip oscillator divided by 8 is selected as
the CPU clock.
If the XIN clock stops oscillating when bits OCD1 to OCD0 in the OCD register are set to 11b, the low-speed
on-chip oscillator automatically starts operating, supplying the necessary clock for the MCU.
The frequency of the low-speed on-chip oscillator varies depending on the supply voltage and the operating
ambient temperature. Application products must be designed with sufficient margin to allow for frequency
changes.
The clock generated by the high-speed on-chip oscillator is used as the clock source for the CPU clock,
peripheral function clock, fOCO, fOCO-F, and fOCO40M.
To use the high-speed on-chip oscillator clock as the clock source for the CPU clock, peripheral clock, fOCO,
and fOCO-F, set bits FRA20 to FRA22 in the FRA2 register as follows:
After reset, the on-chip oscillator clock generated by the high-speed on-chip oscillator stops. Oscillation is
started by setting the FRA00 bit in the FRA0 register to 1 (high-speed on-chip oscillator on). The frequency can
be adjusted by registers FRA1 and FRA2.
Furthermore, frequency correction data corresponding to the supply voltage ranges VCC = 2.2 V to 5.5 V is
stored in FRA6 register. To use separate correction values to match this voltage ranges, transfer them from the
FRA6 register to the FRA1 register.
The frequency correction data of 36.864 MHz is stored in the FRA7 register. To set the frequency of the high-
speed on-chip oscillator to 36.864 MHz, transfer the correction value in the FRA7 register to the FRA1 register
before use.
Since there are differences in the amount of frequency adjustment among the bits in the FRA1 register, make
adjustments by changing the settings of individual bits. Adjust the FRA1 register so that the frequency of the
high-speed on-chip oscillator clock will be 40 MHz or less.
•
•
•
All divide ratio mode settings are supported when VCC = 3.0 V to 5.5 V 000b to 111b
Divide ratio of 4 or more when VCC = 2.7 V to 5.5 V
Divide ratio of 8 or more when VCC = 2.2 V to 5.5 V
On-Chip Oscillator Clocks
Nov 26, 2007
Low-Speed On-Chip Oscillator Clock
High-Speed On-Chip Oscillator Clock
Page 104 of 580
010b to 111b (divide by 4 or more)
110b to 111b (divide by 8 or more)
10. Clock Generation Circuit