Renesas M37544RSS

Overview

M37544RSS from Renesas Electronics is an 8-bit CMOS microcomputer based on the 740 family core, featuring 8 KB ROM, 256 bytes RAM, six-channel 8-bit A/D converter, dual 8-bit timers, one 16-bit timer, UART/clock-synchronized serial I/O, and built-in oscillator circuitry. It operates from 4.0–5.5 V across –20 to +85 °C and targets embedded control in home appliances and office automation equipment.

For engineers reviewing the M37544RSS datasheet, M37544RSS pinout, M37544RSS application, or M37544RSS equivalent, this page delivers verified functional identity, package-specific pin mapping (36PJW-A), real-time interrupt architecture (12 sources/12 vectors), and validated alternative options for cost-sensitive or supply-constrained designs.

Technical Context

The M37544RSS implements the standard 740-family instruction set with 71 basic machine-language instructions and supports double-speed mode for 0.25 µs minimum instruction execution at 8 MHz. Its CPU includes accumulator, index registers X/Y, stack pointer, and processor status register with configurable flags including interrupt disable (I), decimal mode (D), and index X mode (T).

Memory organization comprises 8 KB ROM (user area: 8062 bytes), 256-byte RAM (zero-page and special-page addressing), and dedicated SFR space for peripheral control. Clock generation supports ceramic/quartz crystal, RC, or on-chip oscillator modes, with programmable division ratios (1/1, 1/2, 1/8) and oscillation control bits in CPUM register (003B₁₆).

Key Specifications

Pinout & Package

Package type: 36PJW-A - 0.5 mm-pitch, 36-pin plastic molded SSOP, lead-free compatible, surface-mount.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M37544RSS, the M37544M2-XXXHP offers lower unit cost and guaranteed firmware immutability, while the M37544G2HP provides one-time field programming without emulator hardware dependency-both retain identical I/O, timing, and A/D capabilities but lack on-chip debug support.

Availability

M37544RSS is available at Aetrix Electronics and suitable for home appliance control, office automation equipment, factory automation sensors, and consumer electronics UI requiring stable component supply and long-lifecycle support.

Supply support for M37544RSS 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 is a global semiconductor leader specializing in microcontrollers, analog, and power solutions for industrial, automotive, and consumer markets.

The M37544RSS belongs to the 7544 Group-a family of 8-bit CMOS microcomputers designed for cost-sensitive, resource-constrained embedded control in white goods and office equipment.

FAQ

What is the primary function of the M37544RSS in embedded systems?

The M37544RSS serves as a single-chip 8-bit microcontroller for real-time embedded control tasks. It integrates CPU, memory, A/D conversion, timers, serial I/O, and LED-driving I/O into one device. Its design enables direct interfacing with sensors, actuators, and user interfaces in applications such as microwave ovens and laser printers-eliminating need for external support ICs and reducing system complexity. The M37544RSS executes deterministic control loops using its 740-family instruction set and interrupt architecture.

Does the M37544RSS support in-circuit debugging or emulation?

Yes, the M37544RSS is explicitly designated as the Emulator MCU variant in the 7544 Group. Unlike mask ROM (M37544M2) or OTP PROM (M37544G2) versions, it includes on-chip debug circuitry enabling real-time program download, breakpoint setting, and register inspection via standard emulator hardware. This capability is confirmed in Table 2 of the documentation, which notes "M37544RSS" under "Emulator MCU" with "Only ES version (MP: no plan)" status.

What clock sources does the M37544RSS support, and how are they selected?

The M37544RSS supports three clock sources: external ceramic resonator or quartz crystal (XIN/XOUT), RC network (XIN-XOUT shorted), and internal on-chip oscillator. Selection is controlled by the Oscillation Mode Selection Bit (bit 5) and On-chip Oscillator Oscillation Control Bit (bit 0) in the CPU Mode Register (CPUM at 003B₁₆). These bits are writable once after reset-except for the M37544RSS emulator version, where repeated writes are permitted per documentation note.

How many analog input channels does the M37544RSS provide, and what is their resolution?

The M37544RSS provides six analog input channels (AN0 through AN5) mapped to port P2 pins P20–P25. Each channel supports 8-bit A/D conversion with reference voltage supplied externally via the VREF pin. Conversion accuracy and linearity are specified under standard operating conditions (4.0–5.5 V, –20 to +85 °C), and the A/D control register (ADCON) enables start/stop and channel selection in software.

Is the M37544RSS pin-compatible with other members of the 7544 Group?

The M37544RSS uses the 36PJW-A package (36-pin SSOP), which differs from the 32P4B (SDIP), 32P6U-A (LQFP), and 42S1M (ceramic PIGGY BACK) packages used by other 7544 Group variants. While functional peripherals and register maps are consistent across the group, physical pinout is not interchangeable between packages. Pin compatibility exists only within the same package type-for example, M37544RSS and M37544M2-XXXHP share identical 36PJW-A pin assignments.