Analog Devices Inc./Maxim Integrated DS80C323-END

Overview

DS80C323-END 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 in legacy 8051-based industrial control and instrumentation systems requiring higher throughput without code rewrite.

For engineers reviewing the DS80C323-END datasheet, DS80C323-END pinout, DS80C323-END application, or DS80C323-END equivalent, key selection considerations include its 2.7V–5.5V supply flexibility, programmable MOVX memory access stretch (2–9 cycles), dual data pointer for accelerated block moves, power-fail reset/interrupt, and watchdog timer - all within a 44-pin TQFP package.

Technical Context

The DS80C323-END implements a redesigned 8051 core executing most instructions in 4 oscillator cycles (vs. 12 in standard 80C32), delivering ~2.5× average speedup 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 SCON/SBUF registers and shared Timer 1 for baud rate generation.

Peripherals are controlled via dedicated SFRs including CKCON (8Eh) for MOVX stretch (CKCON.2–0) and timer clock source selection (CKCON.3–5), DPS (86h.0) for DPTR0/DPTR1 switching, and power-fail interrupt enable via IE.2. Timers default to 12-cycle mode at reset for backward timing compatibility but support 4-cycle operation when configured.

Key Specifications

Pinout & Package

DS80C323-END is housed in a 44-pin Thin Quad Flat Package (TQFP) with 0.8mm lead pitch, thermally enhanced for industrial ambient operation. Pin functions align with standard 80C32 layout while adding UART1, INT2–INT5, and T2/T2EX on Port 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-ENL+, DS80C323-END trades maximum clock speed for wider voltage range and lower power - critical for battery-buffered industrial nodes. Against AT89C51ED2-RLTUM, DS80C323-END provides superior real-time peripheral integration (dual UART, power-fail, watchdog) at the cost of on-chip program memory.

Availability

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

Supply support for DS80C323-END 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 high-reliability microcontrollers for industrial, medical, and communications applications.

The DS80C323-END belongs to Maxim's high-speed 8051-compatible microcontroller family, engineered specifically to extend legacy 80C32 designs with enhanced throughput, power resilience, and peripheral integration - without requiring software rewrites.

FAQ

What is the maximum crystal frequency supported by DS80C323-END?

The DS80C323-END supports a maximum crystal frequency of 18MHz, as specified in the official Maxim ordering table for the DS80C323-END variant. This corresponds to a maximum instruction throughput of approximately 4.5 million instructions per second (MIPS) under typical conditions. The device is not rated for operation above 18MHz, and exceeding this limit may result in timing violations or functional failure. DS80C323-END maintains full compatibility with existing 80C32 PCB layouts when used at this frequency.

Does DS80C323-END include on-chip program memory?

No, DS80C323-END does not include on-chip ROM or Flash memory. It is a ROMless microcontroller that requires external program memory accessed via the multiplexed P0 address/data bus and P2 upper address lines. The EA pin must be tied LOW to enable external program fetch. This architecture matches the original 80C32 and allows flexible memory sizing - designers select appropriate EPROM, EEPROM, or NOR Flash based on application code size and update requirements. DS80C323-END provides 256 bytes of on-chip scratchpad RAM only.

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

The dual data pointer (DPTR0 at 82h/83h, DPTR1 at 84h/85h) in DS80C323-END eliminates the need to save and reload address registers during memory block transfers. By toggling the DPS bit (86h.0), software switches between pointers in one instruction cycle. In a 64-byte RAM-to-RAM move, this reduces execution time from 1869 to 1097 machine cycles - a 42% improvement. DS80C323-END's dual DPTR directly accelerates firmware updates, display buffer writes, and protocol packet assembly without additional CPU overhead or external DMA.

Can DS80C323-END operate from a 3.3V supply?

Yes, DS80C323-END is fully specified to operate from 2.7V to 5.5V, making it compatible with standard 3.3V logic systems. Unlike the DS80C320 series (4.25V–5.5V only), DS80C323-END's wider voltage range enables direct integration into mixed-voltage designs - for example, interfacing with 3.3V sensors or communication ICs without level shifters. All I/O pins are 5V-tolerant when VCC ≥ 3.0V, preserving signal integrity in heterogeneous systems. DS80C323-END maintains full functionality, timing, and peripheral operation across this entire supply range.

What is the function of the MOVX stretch feature in DS80C323-END?

The MOVX stretch feature in DS80C323-END, controlled by bits CKCON.2–0 (SFR 8Eh), adjusts the number of machine cycles used for external data memory reads/writes from 2 to 9 cycles. This allows a single DS80C323-END to interface seamlessly with both fast SRAM (e.g., 120ns) and slow peripherals (e.g., LCD controllers or legacy EEPROMs) without external wait-state logic. At reset, stretch defaults to 3 cycles - ensuring compatibility with existing 80C32 designs. DS80C323-END's configurable stretch eliminates board-level glue logic and simplifies BOM by supporting heterogeneous memory/peripheral speeds on one bus.