R5F21257SNFP#U0 Renesas Electronics America, R5F21257SNFP#U0 Datasheet - Page 143

• Manufacturer Part Number: R5F21257SNFP#U0
• Description: IC R8C/25 MCU FLASH 52LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/25r

Specifications of R5F21257SNFP#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 ~ 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
12.6
12.6.1
12.6.2
12.6.3
Do not read address 00000h by a program. When a maskable interrupt request is acknowledged, the CPU reads
interrupt information (interrupt number and interrupt request level) from 00000h in the interrupt sequence. At
this time, the acknowledged interrupt IR bit is set to 0.
If address 00000h is read by a program, the IR bit for the interrupt which has the highest priority among the
enabled interrupts is set to 0. This may cause the interrupt to be canceled, or an unexpected interrupt to be
generated.
Set any value in the SP before an interrupt is acknowledged. The SP is set to 0000h after reset. Therefore, if an
interrupt is acknowledged before setting a value in the SP, the program may run out of control.
Either “L” level or an “H” level of width shown in the Electrical Characteristics is necessary for the signal input
to pins INT0 to INT3 and pins KI0 to KI3, regardless of the CPU clock.
For details, refer to Table 20.21 (VCC = 5V), Table 20.27 (VCC = 3V), Table 20.33 (VCC = 2.2V) External
Interrupt INTi (i = 0 to 3) Input.
Notes on Interrupts
Feb 29, 2008
Reading Address 00000h
SP Setting
External Interrupt and Key Input Interrupt
Page 124 of 485
12. Interrupts