Analog Devices Inc./Maxim Integrated DS80C323-QND

Overview

DS80C323-QND from Maxim Integrated is a high-speed, low-power 80C32-compatible 8-bit microcontroller featuring 4-clock-per-machine-cycle architecture, 18MHz max crystal frequency, -40°C to +85°C industrial temperature range, 256 bytes on-chip RAM, and dual hardware serial ports. It serves as a drop-in upgrade for legacy 8051-based embedded control systems requiring higher throughput without code rewrite.

For engineers reviewing the DS80C323-QND datasheet, DS80C323-QND pinout, DS80C323-QND application, or DS80C323-QND equivalent, key selection considerations include its 2.7V–5.5V supply range, programmable MOVX memory access stretch (2–9 cycles), dual data pointer acceleration, power-fail reset/interrupt, and watchdog timer-critical for industrial monitoring, metering, and real-time control where reliability and timing predictability are essential.

Technical Context

The DS80C323-QND implements a redesigned 8051 core eliminating wasted clock cycles, executing 159 opcodes at 3× speed versus standard 80C32 while maintaining full instruction set and SFR compatibility. Its dual serial ports (UART0 on P3.0/P3.1, UART1 on P1.2/P1.3) operate independently with separate SCON1/SBUF1 registers and shared Timer 1 for baud rate generation.

Timing behavior is configurable via CKCON (SFR 8Eh): default 12-clock timer operation preserves legacy timing, while 4-clock mode enables faster peripherals; MOVX access stretch (CKCON.2–0) adjusts RD/WR strobe width from 2 to 9 machine cycles to interface with diverse memory/peripherals without glue logic.

Key Specifications

Pinout & Package

DS80C323-QND is housed in a 44-pin PLCC (Plastic Leaded Chip Carrier) package with 1.27mm pitch, lead-free/RoHS-compliant construction, and thermal pad omitted - suitable for reflow soldering in industrial PCB assemblies.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-QNG, DS80C323-QND provides wider temperature and voltage ranges critical for field-deployed equipment; compared with AT89C51ED2-RLTUM, it offers pin-compatible legacy upgrade path with hardware features optimized for deterministic real-time control rather than general-purpose embedded computing.

Availability

DS80C323-QND is available at Aetrix Electronics and suitable for industrial PLC modules, smart electricity meters, medical infusion pumps, and building HVAC sensor nodes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DS80C323-QND 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 applications.

The DS80C323-QND belongs to Maxim's high-speed 8051-compatible microcontroller family, designed specifically to extend the life of legacy 8051-based systems through performance upgrades while preserving software and hardware investment.

FAQ

What is the maximum operating frequency and supply voltage range for DS80C323-QND?

The DS80C323-QND supports a maximum crystal frequency of 18MHz and operates across a supply voltage range of 2.7V to 5.5V. This wide VCC range allows direct integration into both 3.3V and 5V legacy systems without level-shifting, and the -40°C to +85°C temperature rating ensures reliability in harsh industrial environments. The DS80C323-QND achieves single-cycle instruction execution in 121ns at 18MHz.

How does DS80C323-QND handle backward compatibility with existing 80C32 firmware?

The DS80C323-QND executes the full 8051 instruction set with identical flag behavior and SFR layout, ensuring binary compatibility for most firmware. Timers default to 12-clock-per-cycle operation on reset to preserve legacy timing, and dual UARTs use non-overlapping SFRs (SCON1/C0h, SBUF1/C1h). The DS80C323-QND requires only minor adjustments for time-critical loops or when enabling 4-clock mode for higher throughput.

Does DS80C323-QND support external memory expansion, and how is it configured?

Yes, DS80C323-QND supports up to 64kB external program memory (ROM/Flash) and 64kB external data memory (RAM/peripherals) using P0 (multiplexed AD0–AD7) and P2 (A8–A15). EA must be tied low to enable external program fetch. MOVX instructions access data space, with strobe timing adjustable via CKCON.2–0 to match memory access times from 2 to 9 machine cycles - eliminating need for external wait-state logic.

What hardware features differentiate DS80C323-QND from standard 80C32 microcontrollers?

The DS80C323-QND adds dual hardware UARTs (UART0 and UART1), programmable MOVX memory access stretch, dual data pointers (DPTR0/DPTR1), early-warning power-fail interrupt, dedicated power-fail reset, and a programmable watchdog timer - all implemented without altering the 8051 instruction set or pinout. These features are accessed via new SFRs (e.g., CKCON at 8Eh, DPS at 86h) that do not conflict with standard 80C32 register addresses.

Is DS80C323-QND pin-compatible with other packages in the DS80C320/DS80C323 family?

Yes, DS80C323-QND is fully pin-compatible with all DS80C320/DS80C323 variants in the same 44-pin PLCC package (e.g., DS80C323-QCD, DS80C323-END). Pin functions, electrical characteristics, and timing parameters are identical across temperature and speed grades within the PLCC footprint. This allows seamless substitution between DS80C323-QND and DS80C323-QCD for commercial-temperature applications without layout changes.