Renesas M38B59EFFS

Overview

M38B59EFFS from Renesas Electronics is an 8-bit single-chip microcomputer in the 740 Family / 38000 Series, featuring on-chip 60 KB mask ROM, 2 KB RAM, a 16-bit timer, UART and I²C-compatible serial I/O, and an 8-channel 10-bit A/D converter. It operates at up to 10 MHz with a 5 V supply and targets embedded control in industrial appliances and office equipment.

For engineers reviewing the M38B59EFFS datasheet, M38B59EFFS pinout, M38B59EFFS application, or M38B59EFFS equivalent, key selection criteria include its 60 KB on-chip mask ROM capacity, 10-bit A/D resolution with sample-and-hold, dual serial interfaces supporting asynchronous and synchronous modes, and support for single-chip mode operation without external ROM.

Technical Context

The M38B59EFFS implements the 740 CPU core with 8-bit data bus and 16-bit address bus, executing instructions in 1–4 clock cycles. It integrates a programmable watchdog timer, interrupt interval determination function, and buzzer output circuit - all controlled via dedicated registers mapped in the 0x00–0xFF I/O space.

Its clock generating circuit supports XIN-based oscillation (1–10 MHz) with internal division options (×1, ÷2, ÷8), and the reset circuit includes both power-on and manual reset inputs. The device uses a single 5 V ±10% supply and meets Standard-grade quality requirements per Renesas classification.

Key Specifications

Pinout & Package

Package: 80-pin plastic quad flat package (QFP), 14 mm × 20 mm body, 0.65 mm lead pitch, standard JEDEC MO-118AC footprint. Thermal pad not present; lead finish is matte tin.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M38B59EFFS, M38B58EFFS provides identical functionality at reduced ROM capacity, while UPD78F0507GC-GAD-AX trades mask-ROM reliability and pin compatibility for Flash flexibility and 16-bit performance - making M38B59EFFS optimal for fixed-function, high-volume, cost-sensitive embedded controllers.

Availability

M38B59EFFS is available at Aetrix Electronics and suitable for industrial control panels, office equipment controllers, home appliance MCUs, and test & measurement front-ends requiring stable component supply and long-term obsolescence management.

Supply support for M38B59EFFS 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 38B5 Group - including M38B59EFFS - was designed for cost-effective, high-reliability embedded control in Standard-grade applications such as office automation, industrial machinery, and consumer appliances.

FAQ

What is the maximum operating frequency of the M38B59EFFS?

The M38B59EFFS supports a maximum main clock frequency of 10 MHz when using an external crystal or ceramic resonator connected to XIN/XOUT. Its internal clock divider allows operation at φ = XIN/2, XIN/8, or XIN depending on CPU mode register settings. The device achieves consistent 10 MHz timing across the industrial temperature range (–20°C to +75°C) under 5.0 V ±10% supply conditions. This frequency governs instruction execution, A/D conversion rate, and serial baud generation for M38B59EFFS.

Does the M38B59EFFS support in-circuit programming?

No, the M38B59EFFS contains mask-programmed ROM and does not support in-circuit programming or field updates. Firmware is permanently embedded during wafer fabrication, ensuring immunity to corruption and deterministic boot behavior. Development requires mask ROM prototyping with Renesas-approved foundries, and revisions necessitate new mask sets. For field-upgradable alternatives, engineers must evaluate Flash-based derivatives outside the 38B5 Group, as M38B59EFFS itself has no ISP, IAP, or bootloader capability.

What are the A/D input channel assignments on the M38B59EFFS?

The M38B59EFFS provides eight analog input channels mapped to Port 0 pins: P00 through P07 serve as AN0 through AN7 respectively. These channels share pins with general-purpose I/O and require software configuration of the ADPC register to enable analog function. The A/D converter uses an internal reference and sample-and-hold circuit, achieving 10-bit resolution with typical INL of ±1 LSB. All channels are scanned sequentially under software or timer trigger control in M38B59EFFS.

Is the M38B59EFFS pin-compatible with other members of the 38B5 Group?

Yes, the M38B59EFFS is fully pin-compatible with other 80-pin QFP variants in the 38B5 Group, including M38B58EFFS and M38B57EFFS. They share identical pin functions, electrical characteristics, and package dimensions (14 mm × 20 mm, 0.65 mm pitch). Differences are limited to mask ROM size (60 KB vs. 48 KB vs. 32 KB) and minor option bits; no PCB layout change is needed when migrating between these variants. This compatibility simplifies design reuse and inventory consolidation for M38B59EFFS and its siblings.

What development tools are officially supported for the M38B59EFFS?

Renesas officially supports the M38B59EFFS with the 740 Family Software Manual (for instruction set and register usage), the "Development Support Tools for Microcomputers" data book (listing ICE units like E8/E8a), and the 38B5 Group User's Manual (covering hardware design, timing, and peripheral initialization). No modern IDE integration exists; legacy toolchains such as the M38K assembler and Renesas E8 emulator are required. Debugging relies on in-circuit emulation via the dedicated EMU0/EMU1 pins, and no JTAG or SWD interface is present on M38B59EFFS.