Renesas M37549G3FP#U2

Overview

M37549G3FP#U2 from Renesas Electronics is an 8-bit CMOS microcontroller based on the 740 family core, featuring 6 KB QzROM, 256 bytes RAM, integrated 10-bit 8-channel A/D converter, UART/clock-synchronous serial interface, and dual-speed on-chip oscillators (4 MHz high-speed, 250 kHz low-speed). It operates from 1.8 V to 5.5 V and targets embedded control in home appliances and factory automation.

For engineers reviewing the M37549G3FP#U2 datasheet, M37549G3FP#U2 pinout, M37549G3FP#U2 application, or M37549G3FP#U2 equivalent, key selection criteria include its PRSP0024GA-A 24-pin SSOP package, built-in power-on reset and low-voltage detection circuits, LED-direct-drive I/O capability, and support for ceramic resonator or 32 kHz crystal clock sources.

Technical Context

The M37549G3FP#U2 implements a standard 740-family CPU with 71 basic instructions, minimum instruction execution time of 0.25 µs at 8 MHz in double-speed mode, and supports both memory-to-memory arithmetic via the T-flag and accumulator-based operations. Its interrupt system delivers 12 sources with dedicated vectors and prioritized servicing.

Peripheral integration includes three 8/16-bit timers (two 8-bit, one 16-bit), 3-channel output compare, 1-channel input capture, and a function set ROM (FFD8–FFDA₁₆) that configures watchdog enable/disable, low-voltage detection validity, and oscillator mode selection at power-up - all without external configuration pins.

Key Specifications

Pinout & Package

Package: PRSP0024GA-A - 24-pin plastic molded SSOP (0.8 mm pitch), RoHS-compliant, surface-mount compatible.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit microcontroller applications.

Compared with M37549G2FP#U2 and M37549G1FP#U2, the M37549G3FP#U2 provides 50% more ROM than G2 and 20% more RAM than G1 - enabling richer feature sets, field-upgradable firmware, and robust error-handling routines without external memory expansion.

Availability

M37549G3FP#U2 is available at Aetrix Electronics and suitable for smart home thermostats, industrial panel controllers, appliance control boards, and energy monitor sensor nodes requiring stable component supply and long-term manufacturing continuity.

Supply support for M37549G3FP#U2 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 industrial, automotive, and IoT applications.

The 7549 Group - including M37549G3FP#U2 - was designed for cost-sensitive, low-power embedded control in consumer and industrial equipment, emphasizing integrated peripherals, flexible clocking, and simplified board design.

FAQ

What is the maximum operating frequency of the M37549G3FP#U2?

The M37549G3FP#U2 supports a maximum external oscillation frequency of 8 MHz when using a ceramic resonator in double-speed mode. Its internal high-speed oscillator operates at 4 MHz typical, and low-speed oscillator at 250 kHz typical - all usable across the full 1.8–5.5 V supply range. The minimum instruction execution time is 0.25 µs under these conditions.

Does the M37549G3FP#U2 include hardware debug support?

The M37549G3FP#U2 does not integrate on-chip debug circuitry such as JTAG or SWD. Debugging is performed via external emulators compatible with the 740 family architecture, or through serial programming interfaces using the built-in QzROM bootloader. Renesas offers the M37549RLSS emulator MCU variant for development purposes.

How is ROM code protection implemented on the M37549G3FP#U2?

ROM code protection on the M37549G3FP#U2 is enforced by writing "00" to address FFDB₁₆ during serial programming. Once set, this disables all read and write access to the QzROM via external programmers. The protection bit is one-time programmable and cannot be cleared after activation - ensuring firmware intellectual property remains secure in production units.

Can the M37549G3FP#U2 operate from a 3.3 V supply?

Yes, the M37549G3FP#U2 operates reliably from 3.3 V across all supported clock modes: it meets specifications for 1.8–5.5 V supply range, including 4 MHz on-chip oscillator (min. 4.0 V), 250 kHz on-chip oscillator (min. 1.8 V), and ceramic resonator configurations down to 2.2 V at 1 MHz. No level-shifting is required for 3.3 V systems.

What peripheral functions are assigned to P10–P17 on the M37549G3FP#U2?

P10–P17 on the M37549G3FP#U2 serve as multifunction pins supporting analog input (AN0–AN7), key-on wakeup interrupt (KEY0–KEY7), and comparator output (CMP0–CMP2). Each pin's function is selected via SFR configuration at runtime - enabling simultaneous use of A/D conversion and hardware key scanning without pin conflict.