Renesas R5F21356MNFP#50

Overview

R5F21356MNFP from Renesas Electronics is a 16-bit R8C CPU core microcontroller with 32 KB flash program ROM, 2.5 KB RAM, and 4 KB data flash (1 KB × 4 blocks) supporting background operation (BGO). It operates at up to 20 MHz (VCC = 2.7–5.5 V), features 47 CMOS I/O ports with pull-up select, and integrates dual 10-bit A/D converters (12 channels), dual 8-bit D/A converters, LIN hardware module, and six timer units including complementary PWM-capable Timer RD for motor control. It targets embedded control in consumer audio and office equipment.

For engineers reviewing the R5F21356MNFP datasheet, R5F21356MNFP pinout, R5F21356MNFP application, or R5F21356MNFP equivalent, key selection criteria include its 52-pin LQFP package, -20°C to +85°C temperature grade (N version), integrated LIN transceiver support via UART0 and Timer RA, BGO-enabled data flash for firmware updates without halting execution, and real-time clock (Timer RE) with calendar-mode timekeeping.

Technical Context

The R5F21356MNFP implements the R8C CPU core with 89 fundamental instructions, 16×16→32-bit multiplier, and multiply-accumulate capability. Its memory map spans 1 Mbyte (00000h–FFFFFh), with program ROM mapped at 08000h–0FFFFh and data flash at 03000h–03FFFh.

It supports four clock sources: XIN (up to 20 MHz crystal/resonator), XCIN (32 kHz crystal), high-speed on-chip oscillator (adjustable), and low-speed on-chip oscillator. Power management includes wait mode (3.5 µA @ 3.0 V, 32 kHz) and stop mode (2.0 µA), with voltage detection circuits for power-on reset and configurable brown-out detection.

Key Specifications

Pinout & Package

Package: 52-pin LQFP (PLQP0052JA-A), 10 mm × 10 mm body, 0.65 mm pin pitch, exposed pad not specified.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit MCU applications.

Compared with R5F21355MNFP and R5F21357MNFP, the R5F21356MNFP delivers optimal balance of code space, RAM, and data flash for mid-tier consumer appliance control-supporting LIN-based diagnostics, real-time motor PWM, and BGO-enabled field updates without over-provisioning memory resources.

Availability

R5F21356MNFP is available at Aetrix Electronics and suitable for audio system control, office equipment motor drive, consumer appliance UI panels, and industrial sensor nodes requiring stable component supply across production lifecycles.

Supply support for R5F21356MNFP 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 specializing in microcontrollers, analog, power, and SoC solutions for automotive, industrial, and IoT markets.

The R8C/35M Group, including R5F21356MNFP, was designed for cost-sensitive, low-power embedded control in consumer electronics-emphasizing integration of LIN, analog peripherals, and BGO flash to reduce system component count and firmware update complexity.

FAQ

What is the maximum operating frequency and supply voltage range for the R5F21356MNFP?

The R5F21356MNFP operates at up to 20 MHz when supplied with 2.7 V to 5.5 V. At lower voltages (1.8 V to 5.5 V), the maximum frequency is reduced to 5 MHz to ensure stable timing margins. This dual-voltage/frequency specification allows flexible power optimization across battery-powered and line-powered designs while maintaining compatibility with legacy 5 V logic interfaces.

Does the R5F21356MNFP support hardware LIN communication, and how is it implemented?

Yes, the R5F21356MNFP includes a dedicated hardware LIN module that combines UART0 and Timer RA to generate and decode LIN 2.0/2.1 frames. This implementation offloads protocol timing and checksum calculation from the CPU, enabling reliable communication with LIN slave nodes (e.g., sensors, actuators) without software bit-banging. The R5F21356MNFP requires only an external LIN transceiver for physical layer compliance.

How does the Background Operation (BGO) function work in the R5F21356MNFP data flash?

The R5F21356MNFP's data flash supports Background Operation (BGO), allowing erase and program operations to execute in parallel with CPU code execution from program ROM. When BGO is enabled, the CPU continues normal operation while flash control logic manages sector erasure and byte/word programming-critical for implementing robust firmware update mechanisms and nonvolatile parameter storage without system interruption.

What are the real-time clock capabilities of the R5F21356MNFP, and how is it powered in low-power modes?

The R5F21356MNFP implements real-time clock functionality in Timer RE, which counts seconds, minutes, hours, and days of week using the 32 kHz XCIN crystal oscillator. In stop mode, Timer RE remains active with only 2.0 µA current draw at 3.0 V, enabling accurate timekeeping during extended sleep periods. Calendar-mode operation requires initialization of the RE register set but imposes no additional software overhead during runtime.

Can the R5F21356MNFP generate complementary PWM waveforms for three-phase motor control?

Yes, Timer RD in the R5F21356MNFP supports complementary PWM mode with hardware dead-time insertion and three-phase waveform generation across six output pins (P2_0–P2_5). This capability enables direct control of BLDC or PMSM inverters without external gate drivers or timing-critical software routines-reducing EMI and improving torque smoothness in fan, pump, and compressor applications.