Renesas R5F21237JFP

Overview

R5F21237JFP from Renesas Electronics is a 16-bit R8C/23 Group microcontroller with CAN 2.0B interface, 48 KB program flash, 2.5 KB RAM, and 2 KB data flash (1 KB × 2 blocks), housed in a 48-pin LQFP package. It features a 10-bit 12-channel ADC, dual UARTs, I²C, LIN, and multiple 8-/16-bit timers - optimized for automotive body control and industrial FA networking.

For engineers reviewing the R5F21237JFP datasheet, R5F21237JFP pinout, R5F21237JFP application, or R5F21237JFP equivalent, key selection considerations include its -40°C to +85°C operating range, integrated CAN transceiver support, on-chip high-speed oscillator with frequency adjustment, and data flash endurance of 10,000 write/erase cycles for parameter storage.

Technical Context

The R5F21237JFP implements the R8C CPU core with 89 fundamental instructions and executes at 50 ns minimum instruction time (20 MHz XIN, 3.0–5.5 V). Its memory architecture includes separate program ROM and dedicated 2 KB data flash (1 KB × 2 blocks) mapped at 02400h–02BFFh, enabling reliable nonvolatile parameter retention independent of firmware updates.

Peripheral integration centers on real-time control: Timer RD provides two 16-bit channels with input capture/output compare; CAN module supports 16 message slots and full 2.0B compliance; LIN is hardware-accelerated using Timer RA and UART0; and A/D conversion operates across 12 analog inputs with 10-bit resolution and programmable sampling timing.

Key Specifications

Pinout & Package

Package: 48-pin plastic LQFP (PLQP0048KB-A), 7 mm × 7 mm body, 0.5 mm lead pitch, exposed pad not specified. Compliant with JEDEC MS-026 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with R5F21237KFP and R5F21227JFP, the R5F21237JFP uniquely balances industrial-grade temperature range (-40°C to +85°C), integrated data flash for field-updatable calibration, and CAN/LIN coexistence - making it optimal for cost-constrained, safety-aware embedded nodes requiring local nonvolatile storage.

Availability

R5F21237JFP is available at Aetrix Electronics and suitable for automotive body electronics, industrial fieldbus nodes, smart HVAC controllers, and medical diagnostic equipment interfaces requiring stable component supply and long-term lifecycle support.

Supply support for R5F21237JFP 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/23 Group, including R5F21237JFP, was designed for cost-sensitive, real-time embedded applications in automotive and industrial environments where CAN networking, analog sensing, and local data storage are essential.

FAQ

What is the maximum operating frequency of the R5F21237JFP?

The R5F21237JFP supports a maximum external clock frequency of 20 MHz via the XIN/XOUT pins. When using the internal high-speed oscillator, the achievable frequency depends on trimming settings but is calibrated to support 20 MHz operation. The minimum instruction execution time is 50 ns under these conditions (VCC = 3.0–5.5 V), confirming full 20 MHz capability for time-critical tasks in the R5F21237JFP.

Does the R5F21237JFP include on-chip debug support?

Yes, the R5F21237JFP includes on-chip debugging capability via the single-wire background debugger interface. It supports breakpoints, watchpoints, and real-time register/memory access without halting peripheral operation. Debug resources occupy memory addresses 20000h–23FFFh, which must be excluded from application code - a requirement explicitly documented for the R5F21237JFP in the hardware manual.

How is the data flash organized in the R5F21237JFP?

The R5F21237JFP contains 2 KB of data flash, structured as two independent 1 KB blocks located at memory addresses 02400h–027FFh and 02800h–02BFFh. Each block supports 10,000 write/erase cycles and can be programmed/erased separately. This layout allows one block to store active parameters while the other holds backup or versioned data - a key reliability feature of the R5F21237JFP.

Can the R5F21237JFP operate without an external crystal?

Yes, the R5F21237JFP can operate using its built-in high-speed on-chip oscillator, which is factory-trimmed and software-adjustable. This eliminates the need for external crystals in applications where timing precision less than ±1% is acceptable. However, for CAN or LIN communication requiring strict baud rate accuracy, an external crystal (e.g., 20 MHz) connected to XIN/XOUT is recommended - a validated configuration for the R5F21237JFP.

What peripheral modules are shared with the R5F21227JFP?

The R5F21237JFP shares identical peripheral functionality with the R5F21227JFP - including UART0/UART1, I²C, LIN (Timer RA + UART0), CAN, 10-bit 12-channel ADC, and all timers (RA, RB, RD, RE) - except for the presence of 2 KB data flash. Pinout, memory map layout (excluding data flash region), and register-level programming model are fully compatible, enabling drop-in replacement where data flash is unused - confirmed for both R5F21237JFP and R5F21227JFP.