Analog Devices Inc./Maxim Integrated DS80C323-QND+

Overview

DS80C323-QND+ from Maxim Integrated is a high-speed, low-power 80C32-compatible 8-bit microcontroller with 4-clock-per-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 faster 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 for block transfers, power-fail reset/interrupt, and watchdog timer - all in a 44-pin PLCC package.

Technical Context

The DS80C323-QND+ implements a redesigned 8051 core executing most instructions in 4 oscillator cycles (vs. 12 in standard 80C32), delivering ~2.5× average speedup. Its dual SFR-mapped serial ports (UART0 on P3.0/P3.1, UART1 on P1.2/P1.3) operate independently with configurable baud rates using Timer 1 (UART1) or Timer 1/2 (UART0).

Peripheral timing is decoupled: timers default to 12-cycle mode for backward compatibility but can be reconfigured via CKCON register (SFR 8Eh) to 4-cycle operation; MOVX access speed is software-selectable (2–9 machine cycles) using CKCON.2–0 bits, enabling seamless interfacing with both fast SRAM and slow peripherals like LCDs or legacy UARTs.

Key Specifications

Pinout & Package

DS80C323-QND+ is housed in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead geometry, lead-free/RoHS-compliant finish, and thermal characteristics suitable for convection-cooled industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8051-compatible microcontroller applications.

Compared with DS80C320-QNG+, DS80C323-QND+ trades maximum clock speed for wider voltage range and industrial temp grade; compared with AT89C51ED2-RLTUM, it offers superior real-time peripheral control via hardware-configurable MOVX and dual UARTs - critical for deterministic industrial communication stacks.

Availability

DS80C323-QND+ is available at Aetrix Electronics and suitable for industrial PLC modules, smart energy meters, medical infusion pumps, and building automation gateways requiring stable component supply across extended temperature and voltage ranges.

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 legacy 8051 system lifecycles with measurable performance gains while preserving software and hardware investment.

FAQ

What is the maximum crystal frequency supported by DS80C323-QND+?

The DS80C323-QND+ supports a maximum crystal frequency of 18MHz, enabling single-cycle instruction execution in as little as 222ns. This is specified in the Ordering Information table and confirmed in the Detailed Description section of the datasheet. The device achieves this while maintaining full 80C32 instruction set compatibility and operating across the -40°C to +85°C industrial temperature range.

Does DS80C323-QND+ include on-chip program memory?

No, DS80C323-QND+ does not include on-chip ROM or Flash program memory. It is a ROMless variant requiring external program memory accessed via the multiplexed P0 address/data bus and P2 high-order address lines. The EA pin must be tied LOW to enable external program fetches, as stated in the PIN DESCRIPTION section and confirmed in the MEMORY ACCESS subsection.

How does the dual data pointer in DS80C323-QND+ improve performance?

The dual data pointer (DPTR0 at 82h/83h, DPTR1 at 84h/85h) in DS80C323-QND+ reduces 64-byte RAM-to-RAM block moves by 772 machine cycles versus single-DPTR code - cutting execution time from 299μs to 175.5μs at 25MHz. This is achieved by eliminating address reload overhead, as demonstrated in the provided assembly examples in the datasheet's DUAL DATA POINTER section.

Can DS80C323-QND+ operate from a 3.3V supply?

Yes, DS80C323-QND+ supports operation from 2.7V to 5.5V, making it compatible with 3.3V systems. This is explicitly stated in the DETAILED DESCRIPTION ("DS80C323 offers the same feature set… but with 2.7V to 5.5V operation") and confirmed in the PIN DESCRIPTION table where VCC is labeled "+5V (+3V for DS80C323)". No level-shifting is required for 3.3V I/O interfaces.

What peripheral functions are enabled by the CKCON register in DS80C323-QND+?

The CKCON register (SFR 8Eh) in DS80C323-QND+ controls two critical timing features: bits CKCON.2–0 configure MOVX instruction access stretch (2–9 machine cycles), and bits CKCON.3–5 independently select 4- or 12-clock-per-cycle timing for Timers 0, 1, and 2. This allows precise tuning of memory/peripheral interface timing and timer resolution without affecting CPU instruction speed.