Renesas RX74M/RX74N industrial MCUs debut 600MHz RXv3e core with embedded MRAM

Renesas has launched the RX74M and RX74N, two 32-bit industrial MCUs fabricated on a 22nm process that introduce embedded MRAM to the company's proprietary RX architecture. Both parts feature a 600MHz RXv3e core with up to 3,604 CoreMark performance, paired with 1MB of code MRAM, 1.5MB SRAM, and 256KB of zero-wait-state local RAM for deterministic real-time workloads.

The RX74M targets advanced industrial networking with dual Gigabit Ethernet MACs, TSN-capable Ethernet switching, and an integrated EtherCAT slave controller, while the RX74N provides a single Gigabit Ethernet interface for less demanding applications. Both include CAN FD, USB 2.0, I3C, high-resolution PWM, and hardware security through the RSIP-E50D engine with Protect Zone isolation. Software support spans the Renesas FSP, e² studio IDE, and third-party tools including Zephyr RTOS and PROFINET stacks from Codewerk and RT-Labs.

MRAM architecture and industrial networking differentiation

• MRAM memory hierarchy: Up to 1MB code MRAM with dual-bank support replaces traditional flash, enabling faster in-field reprogramming; 48KB data MRAM rated for 100,000 cycles and 128KB user extra MRAM configurable as MTJ-OTP provide flexible non-volatile storage options.
• RXv3e core performance: 600MHz operation with 32KB instruction and data caches (both ECC-protected), single/double-precision FPU, trigonometric accelerator, and register bank save for accelerated interrupt response; 256KB local RAM offers zero-wait-state access for hard real-time tasks.
• Networking differentiation: RX74M adds dual Gigabit Ethernet MACs, 2-port TSN switch, and 2-port EtherCAT slave controller; RX74N scales to single Gigabit Ethernet without TSN or EtherCAT, targeting cost-sensitive industrial nodes.
• Security subsystem: RSIP-E50D engine implements AES, RSA, ECC, ChaCha20-Poly1305, SHA-512/SHA3-512, and TRNG; Protect Zone hardware separates secure/non-secure execution with secure boot, lifecycle management, tamper detection, key zeroization, and on-the-fly external memory decryption.
• Expansion and storage interfaces: Dual xSPI with Octal Flash/RAM execute-in-place and on-the-fly decryption, external SDRAM to 128MB, SD/MMC host, parallel camera capture, and I2S/PDM audio interfaces.

Why it matters

The RX74M and RX74N strengthen Zephyr RTOS's position in industrial automation by adding another high-performance target with native vendor support, complementing existing Cortex-M85-based RA8 parts. For open hardware practitioners, the MRAM-based code storage eliminates flash wear-out concerns and enables faster firmware iteration, though the proprietary RXv3e architecture lacks the open ISA ecosystem momentum of RISC-V alternatives. The evaluation kits with Arduino Uno R3, mikroBUS, and Pmod headers provide accessible prototyping paths for motor control and industrial networking projects.