Renesas R5F21124FP#U0

Overview

R5F21124FP#U0 from Renesas Electronics is a 16-bit R8C/Tiny Series microcontroller in a 32-pin LQFP package, featuring 16 KB flash program ROM, 1 KB RAM, and 2 KB × 2 data flash blocks. It integrates an 8-bit timer X/Y/Z, 16-bit timer C with input capture, dual UART/serial interfaces, 10-bit 8-channel ADC, and watchdog timer. It targets embedded control in household appliances and industrial sensor systems operating at 3.0–5.5 V.

For engineers reviewing the R5F21124FP#U0 datasheet, R5F21124FP#U0 pinout, R5F21124FP#U0 application, or R5F21124FP#U0 equivalent, key selection criteria include its -40°C to +85°C industrial temperature grade (D-version), on-chip oscillator support, LED drive port capability on P10–P17, and data flash endurance of 10,000 erase/write cycles for firmware updates and parameter storage.

Technical Context

The R5F21124FP#U0 implements the R8C Tiny Series CPU core with 89 basic instructions and executes at 62.5 ns minimum instruction time (16 MHz XIN, 3.0–5.5 V). Its memory map allocates 1 MB address space, with fixed interrupt vectors at 0FFDC₁₆–0FFFF₁₆, program ROM starting at 0C000₁₆, and data flash at 02000₁₆–02FFF₁₆.

Peripheral control uses Special Function Registers (SFRs) mapped to 00000₁₆–002FF₁₆, including WDTS/WDC for watchdog configuration, CM0/CM1 for clock generation, and S0TIC/S0RIC for UART0 interrupt control. Reset is active-low via the dedicated /RESET pin with external pull-up resistor.

Key Specifications

Pinout & Package

Package: PLQP0032GB-A (32-pin plastic LQFP, 7 mm × 7 mm, 0.8 mm pitch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with R5F21124FP#U0, R5F21124DFP offers identical functionality in tape-and-reel format for production lines, while R5F21123FP reduces memory capacity by 4 KB but retains full peripheral compatibility - enabling scalable design reuse across product tiers without layout changes.

Availability

R5F21124FP#U0 is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance control modules, and office equipment requiring stable component supply over extended production lifecycles.

Supply support for R5F21124FP#U0 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a global semiconductor leader formed in 2010 through the merger of NEC Electronics and Renesas Technology, specializing in microcontrollers, analog, and power solutions.

The R8C/12 Group, including R5F21124FP#U0, was designed for cost-sensitive, low-power embedded control in consumer and industrial applications - emphasizing integrated peripherals, flash flexibility, and wide operating temperature range.

FAQ

What is the maximum operating frequency supported by the R5F21124FP#U0?

The R5F21124FP#U0 supports a maximum external clock frequency of 16 MHz when powered at 3.0–5.5 V, achieving a minimum instruction execution time of 62.5 ns. At 10 MHz, it operates down to 2.7 V, making it adaptable to both 3.3 V and 5 V system rails. The on-chip oscillator provides a lower-accuracy internal clock option for reduced BOM count.

Does the R5F21124FP#U0 include hardware debugging support?

Yes, the R5F21124FP#U0 supports on-chip debugging via dedicated pins (P00/AN7/TxD11 and P37/TxD10/RxD1), though these pins must be unused during debug session. The MCU implements Renesas' standard debug interface compatible with E8/E8a emulators, enabling breakpoints, register inspection, and flash programming without external JTAG hardware.

How is the data flash memory organized in the R5F21124FP#U0?

The R5F21124FP#U0 contains two independent 2 KB data flash blocks (Block A and Block B) located at memory addresses 02000₁₆–02FFF₁₆. Each block supports 10,000 erase/write cycles and can be programmed in byte, word, or block units. This structure allows wear leveling and safe firmware parameter storage separate from program ROM.

Can the R5F21124FP#U0 operate from a single 3.3 V supply?

Yes, the R5F21124FP#U0 operates reliably from a 3.3 V supply when configured for 10 MHz maximum clock frequency (VCC = 2.7–5.5 V). At 3.3 V, typical active current is 5 mA, and Stop mode draws only 0.7 µA - making it well-suited for battery-powered or energy-efficient designs where 3.3 V regulation is standard.

What peripheral functions are shared with I/O pins on the R5F21124FP#U0?

Multiple I/O pins on the R5F21124FP#U0 serve dual roles: P00–P07 double as ADC inputs AN0–AN7; P10–P17 function as LED drive ports; P15/P14 are UART0 RxD0/TxD0; P37/P30 are UART1 TxD10/RxD1 and Timer C input CNTR0; and P45 is both INT0 interrupt input and general-purpose input. Pin function selection is controlled via SFR settings.