Analog Devices Inc./Maxim Integrated DS2250-64-16

Overview

DS2250-64-16 from Maxim Integrated is an 8-bit 8051-compatible soft microcontroller module featuring 64kB of nonvolatile CMOS SRAM for program and data storage, 16MHz maximum crystal speed, 32 parallel I/O lines, and full-duplex on-chip UART - deployed in secure industrial control systems requiring persistent firmware retention after power loss.

For engineers reviewing the DS2250-64-16 datasheet, DS2250-64-16 pinout, DS2250-64-16 application, or DS2250-64-16 equivalent, key selection criteria include nonvolatile RAM endurance (10 years at room temperature), power-fail reset/interrupt capability, serial bootstrap loader support at multiple baud rates, and compatibility with standard 8051 development tools.

Technical Context

The DS2250-64-16 implements a fully 8051-object-code-compatible CPU core with internal nonvolatile SRAM mapped across separate 64kB program and 64kB data address spaces. Its memory architecture supports dynamic partitioning between code and data via MCON register configuration, enabling flexible runtime allocation within the 64kB NV RAM.

It integrates dual timer/event counters, two external interrupt inputs (INT0/INT1), expanded bus interface with ALE/PSEN/WR/RD control, and a serial port operating in Mode 0 (shift register) or Mode 1 (asynchronous). No real-time clock is included in the DS2250-64-16 variant - that functionality requires the 'T' suffix (e.g., DS2250T-64-16).

Key Specifications

Pinout & Package

DS2250-64-16 uses a 40-pin SIMM (Single In-line Memory Module) package measuring 2.65″ × 2.385″ × 0.85″ (L×W×H), with gold-plated edge contacts and industry-standard pin spacing. The module is designed for socketed insertion into compatible carrier boards.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar soft microcontroller applications.

Compared with DS2250-32-16, the DS2250-64-16 doubles available nonvolatile memory for larger firmware or extended data buffers; compared with DS2250T-64-16, it omits the RTC subsystem to reduce cost and board area - making it optimal for pure control applications without time-of-day dependency.

Availability

DS2250-64-16 is available at Aetrix Electronics and suitable for industrial data loggers, secure metering terminals, medical device controllers, and legacy system retrofit modules requiring stable component supply and long-term obsolescence management.

Supply support for DS2250-64-16 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and embedded security ICs for industrial, medical, and communications applications.

The DS2250 product line delivers "soft" microcontrollers with integrated nonvolatile SRAM - engineered for applications demanding firmware persistence, field-upgradability, and tamper-resistant operation without external memory or batteries.

FAQ

What is the nonvolatile memory technology used in the DS2250-64-16?

The DS2250-64-16 uses nonvolatile CMOS SRAM technology, not flash or EEPROM. This allows unlimited write cycles, byte-level access, and full retention of program and data memory for over 10 years at room temperature without power. Unlike flash, it does not require erase-before-write sequences and supports true self-modifying code execution - all verified in the DS2250-64-16 datasheet's MEMORY ORGANIZATION section.

Does the DS2250-64-16 include a real-time clock (RTC)?

No, the DS2250-64-16 does not include a real-time clock. The 'T' suffix (e.g., DS2250T-64-16) denotes models with an integrated RTC and on-board crystal. The DS2250-64-16 datasheet explicitly lists "TIMEKEEPING?" as "No" in the ORDERING INFORMATION table and omits RTC register descriptions - confirming absence of timekeeping hardware in this variant.

How is firmware loaded into the DS2250-64-16 during production?

Firmware is loaded into the DS2250-64-16 via its serial bootstrap loader using a standard UART interface at baud rates from 300 to 9600 bps - supported by the L command accepting Intel HEX format. Alternatively, parallel programming is possible using an 87C51H-compatible protocol with VPP=13V pulses. Both methods are documented in the DS2250-64-16 PROGRAM LOADING section and require RST high + PSEN low to enter load mode.

What is the purpose of the MCON register in the DS2250-64-16?

The MCON register in the DS2250-64-16 controls memory configuration and security features: bit ECE2 (MCON.2) selects alternate data memory maps for RTC access (not used in DS2250-64-16), bit MCON.0 enables the security lock, and other bits configure RAM partitioning between program and data space. It is written using the W command in serial loader mode or via MOV instructions in firmware - per the DS2250-64-16 Secure Microcontroller User's Guide.

Is the DS2250-64-16 RoHS-compliant?

Yes, the DS2250-64-16 is RoHS-compliant. The ordering information table specifies that variants with a '+' suffix (e.g., DS2250-64-16+) denote lead-free/RoHS-compliant packages, while the base DS2250-64-16 is also RoHS-compliant per Maxim's documentation - confirmed by its listing in the RoHS-compliant devices section of the 060906 revision datasheet.