Analog Devices Inc./Maxim Integrated DS80C320-MEL

Overview

DS80C320-MEL from Maxim Integrated is a high-speed, 80C32-compatible 8-bit microcontroller featuring a 4-clock-per-machine-cycle core, 33MHz maximum crystal frequency, 256 bytes of on-chip RAM, dual hardware serial ports, and programmable watchdog timer. It operates from 4.25V to 5.5V and targets legacy 8051 system upgrades requiring deterministic real-time control in industrial automation and embedded instrumentation.

For engineers reviewing the DS80C320-MEL datasheet, DS80C320-MEL pinout, DS80C320-MEL application, or DS80C320-MEL equivalent, this page delivers verified electrical parameters, validated package mapping (40-pin DIP), confirmed pin functions per Maxim's official pinout diagram, and two rigorously cross-checked alternative parts for drop-in or functional replacement scenarios.

Technical Context

The DS80C320-MEL implements a redesigned 8051-compatible core eliminating wasted clock cycles-executing most instructions in 4 oscillator clocks versus 12 in standard 80C32, yielding up to 3× speed improvement at identical crystal frequency. Its memory interface supports 64kB ROM and 64kB RAM addressing with variable MOVX timing (2–9 machine cycles) controlled via CKCON register bits 2–0.

It integrates seven additional interrupt sources beyond standard 80C32-including INT2 through INT5 on Port 1-and provides dual data pointers (DPTR0/DPTR1) at SFR addresses 82h–85h with DPS bit at 86h LSB, enabling zero-overhead switching during block memory transfers. Timer/counter operation defaults to 12-clock mode for backward compatibility but can be reconfigured to 4-clock mode via CKCON.4–.5.

Key Specifications

Pinout & Package

DS80C320-MEL is supplied in a 40-pin plastic dual in-line package (DIP), with pin 1 located at bottom-left corner when notch faces upward. All pins conform to industry-standard 80C32 pinout layout, ensuring mechanical and electrical compatibility with existing sockets and PCB footprints.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-MCL, DS80C320-MEL offers extended temperature operation and non-RoHS packaging for legacy manufacturing lines; compared with DS80C323-MCD, it delivers 83% higher clock speed and power-fail warning capability essential for industrial reliability-neither alternative matches its combination of speed, temperature range, and fault-handling features.

Availability

DS80C320-MEL is available at Aetrix Electronics and suitable for industrial automation, embedded instrumentation, and legacy 8051 system upgrades requiring stable component supply across long production lifecycles.

Supply support for DS80C320-MEL 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) is a semiconductor company specializing in precision analog, mixed-signal, and high-reliability microcontrollers for industrial, medical, and communications markets.

The DS80C320-MEL belongs to Maxim's high-speed 8051-compatible microcontroller family, designed specifically to extend the lifecycle of legacy 80C32-based systems while delivering measurable performance gains without software or hardware redesign.

FAQ

What is the maximum crystal frequency supported by DS80C320-MEL?

The DS80C320-MEL supports a maximum crystal frequency of 33MHz, enabling an apparent instruction execution rate of approximately 82.5MHz due to its 4-clock-per-machine-cycle architecture. This specification is explicitly stated in Maxim's official ordering information table and confirmed in the Detailed Description section of the datasheet. The DS80C320-MEL achieves this speed without requiring external clock multipliers or PLL circuits.

Does DS80C320-MEL include on-chip program memory (ROM/Flash)?

No, the DS80C320-MEL does not contain on-chip program memory. As confirmed in the Memory Access section of the datasheet, it relies entirely on external ROM or Flash memory accessed via the multiplexed P0 address/data bus and P2 upper address lines. The device includes 256 bytes of on-chip scratchpad RAM but requires EA pin (Pin 31) to be tied LOW to enable external program memory access-this is a defining architectural trait of the DS80C320-MEL.

How many hardware serial ports does DS80C320-MEL provide, and where are they located?

The DS80C320-MEL provides two independent full-duplex hardware UARTs. UART0 uses Port 3 pins P3.0 (RXD0) and P3.1 (TXD0); UART1 uses Port 1 pins P1.2 (RXD1) and P1.3 (TXD1). This dual-serial capability is documented in the FEATURES list and detailed in the PERIPHERAL OVERVIEW section, enabling simultaneous communication with multiple devices without software emulation or time-slicing.

What is the function of the DPS bit in DS80C320-MEL, and where is it located?

The DPS (Data Pointer Select) bit controls selection between the two data pointers (DPTR0 and DPTR1) in the DS80C320-MEL. It resides at the least-significant bit of Special Function Register 86h (SFR address 86h), as specified in the DUAL DATA POINTER section. Writing '1' to DPS activates DPTR1 (SFR addresses 84h/85h); writing '0' selects DPTR0 (82h/83h). This mechanism enables efficient block memory moves without register save/restore overhead in DS80C320-MEL firmware.

Is DS80C320-MEL pin-compatible with standard 80C32 microcontrollers?

Yes, the DS80C320-MEL is fully pin-compatible with the standard 80C32 in the 40-pin DIP package, as explicitly stated in the 80C32 COMPATIBILITY section. It retains identical pin functions for VCC, GND, RST, XTAL1/XTAL2, P0–P3, EA, ALE, PSEN, WR, and RD. This compatibility allows direct replacement in existing 80C32 designs, though firmware timing adjustments may be needed due to the DS80C320-MEL's faster instruction execution.