R5F21257SYFP#U0 Renesas Electronics America, R5F21257SYFP#U0 Datasheet - Page 102
![MCU 2KB FLASH 48K 52-LQFP](/photos/28/61/286101/52-lqfp_sml.jpg)
R5F21257SYFP#U0
Manufacturer Part Number
R5F21257SYFP#U0
Description
MCU 2KB FLASH 48K 52-LQFP
Manufacturer
Renesas Electronics America
Series
R8C/2x/25r
Specifications of R5F21257SYFP#U0
Core Processor
R8C
Core Size
16/32-Bit
Speed
20MHz
Connectivity
I²C, LIN, SIO, SSU, UART/USART
Peripherals
POR, Voltage Detect, WDT
Number Of I /o
41
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
Oscillator Type
Internal
Operating Temperature
-20°C ~ 105°C
Package / Case
52-LQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
- Current page: 102 of 527
- Download datasheet (6Mb)
R8C/24 Group, R8C/25 Group
Rev.3.00
REJ09B0244-0300
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.
The frequency correction data (the value is the same as that of the FRA1 register after a reset) corresponding to
the supply voltage ranges VCC = 2.7 V to 5.5 V is stored in FRA4 register. Furthermore, the 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 these voltage ranges, transfer them from FRA4 or 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. This enables the setting errors of bit rates such as 9600 bps and 38400 bps to be 0% when the serial
interface is used in UART mode (refer to Table 15.7 Bit Rate Setting Example in UART Mode (Internal
Clock Selected)).
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
Feb 29, 2008
Low-Speed On-Chip Oscillator Clock
High-Speed On-Chip Oscillator Clock
Page 83 of 485
010b to 111b (divide by 4 or more)
110b to 111b (divide by 8 or more)
10. Clock Generation Circuit
Related parts for R5F21257SYFP#U0
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![R0K330290S001BE](/photos/28/41/284146/r0k330290s001be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR M16C/29
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K5212D8S001BE](/photos/24/13/241324/4607177_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8C/2D
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K33062PS001BE](/photos/24/13/241320/4607173_tmb.jpg)
Part Number:
Description:
R0K33062P STARTER KIT
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K521237S001BE](/photos/28/41/284170/r0k521237s001be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8C/23 E8A
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K521256S001BE](/photos/24/13/241323/4607176_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8C/25
Manufacturer:
Renesas Electronics America
Datasheet:
![YLCDRSK2456S](/images/manufacturer_photos/0/5/560/renesas_electronics_america_tmb.jpg)
Part Number:
Description:
KIT STARTER H8S2456 SHARPE DSPLY
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K521380S000BE](/photos/28/41/284144/r0k521380s000be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8C38C
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K521350S000BE](/photos/28/41/284145/r0k521350s000be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8C35C
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K52L3A0S000BE](/photos/28/41/284149/r0k52l3a0s000be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R8CL3AC+LCD APPS
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K556100S000BE](/images/manufacturer_photos/0/5/560/renesas_electronics_america_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR RX610
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K564189S000BE](/photos/28/41/284173/r0k564189s000be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR R32C/118
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K521276S000BE](/photos/9/26/92647/r0k521276s000be_tmb.jpg)
Part Number:
Description:
KIT DEV RSK-R8C/26-29
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K571242S001BE](/photos/9/23/92397/r0k571242s001be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR SH7124
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K561622S000BE](/photos/9/23/92398/r0k561622s000be_tmb.jpg)
Part Number:
Description:
KIT STARTER FOR H8SX/1622
Manufacturer:
Renesas Electronics America
Datasheet:
![R0K572030S000BE](/photos/9/24/92406/r0k572030s000be_tmb.jpg)
Part Number:
Description:
KIT DEV FOR SH7203
Manufacturer:
Renesas Electronics America
Datasheet: