R5F21257SNFP#U0 Renesas Electronics America, R5F21257SNFP#U0 Datasheet - Page 132

• 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
Figure 12.10
12.1.6.8
12.1.6.9
When the REIT instruction is executed at the end of an interrupt routine, the FLG register and PC, which have
been saved to the stack, are automatically restored. The program, that was running before the interrupt request
was acknowledged, starts running again.
Restore registers saved by a program in an interrupt routine using the POPM instruction or others before
executing the REIT instruction.
If two or more interrupt requests are generated while a single instruction is being executed, the interrupt with
the higher priority is acknowledged.
Set bits ILVL2 to ILVL0 to select the desired priority level for maskable interrupts (peripheral functions).
However, if two or more maskable interrupts have the same priority level, their interrupt priority is resolved by
hardware, and the higher priority interrupts acknowledged.
The priority levels of special interrupts, such as reset (reset has the highest priority) and watchdog timer, are set
by hardware.
Figure 12.10 shows the Priority Levels of Hardware Interrupts.
The interrupt priority does not affect software interrupts. The MCU jumps to the interrupt routine when the
instruction is executed.
Feb 29, 2008
Returning from an Interrupt Routine
Interrupt Priority
Priority Levels of Hardware Interrupts
Page 113 of 485
Oscillation stop detection
Peripheral function
Voltage monitor 1
Voltage monitor 2
Watchdog timer
Address match
Address break
Single step
Reset
High
Low
12. Interrupts