R5F21256SNFP#U0 Renesas Electronics America, R5F21256SNFP#U0 Datasheet - Page 498

• Manufacturer Part Number: R5F21256SNFP#U0
• Description: IC R8C MCU FLASH 32K 52LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/25r

Specifications of R5F21256SNFP#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: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 52-LQFP
• For Use With: R0K521256S000BE - KIT EVAL STARTER FOR R8C/25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/24 Group, R8C/25 Group
Rev.3.00
REJ09B0244-0300
21.9
21.9.1
21.9.2
Connect a bypass capacitor (at least 0.1 µF) using the shortest and thickest write possible.
During rigorous noise testing or the like, external noise (mainly power supply system noise) can exceed the
capacity of the MCU's internal noise control circuitry. In such cases the contents of the port related registers
may be changed.
As a firmware countermeasure, it is recommended that the port registers, port direction registers, and pull-up
control registers be reset periodically. However, examine the control processing fully before introducing the
reset routine as conflicts may be created between the reset routine and interrupt routines.
Notes on Noise
Feb 29, 2008
Inserting a Bypass Capacitor between VCC and VSS Pins as a Countermeasure
against Noise and Latch-up
Countermeasures against Noise Error of Port Control Registers
Page 479 of 485
21. Usage Notes