Analog Devices Inc./Maxim Integrated DS80C320-FCG+

Overview

DS80C320-FCG+ from Maxim Integrated is a high-speed, 80C32-compatible 8-bit microcontroller with 4-clock-per-machine-cycle architecture, 256 bytes of on-chip RAM, three 16-bit timer/counters, and dual hardware serial ports. It operates at up to 33MHz (82.5MHz effective throughput), supports 64kB external program and data memory addressing, and delivers 2.5× average instruction speedup over standard 8051 cores - used in industrial control panels requiring deterministic real-time I/O response.

For engineers reviewing the DS80C320-FCG+ datasheet, DS80C320-FCG+ pinout, DS80C320-FCG+ application, or DS80C320-FCG+ equivalent, key selection considerations include its 40-pin CERDIP package, programmable MOVX memory access stretch (2–9 cycles), dual data pointer for accelerated block transfers, power-fail reset/interrupt capability, and compatibility with legacy 80C32 PCB layouts while enabling performance upgrades without firmware rewrite.

Technical Context

The DS80C320-FCG+ implements a redesigned 8051 core eliminating dummy clock cycles, executing most instructions in 4 oscillator clocks versus 12 in legacy 80C32 - achieving 3× speed for 159 opcodes. Its dual-data-pointer architecture (DPTR0 at 82h/83h, DPTR1 at 84h/85h) enables zero-overhead switching between source/destination addresses during memory moves.

Peripherals include two independent full-duplex UARTs (Serial Port 0 on P3.0/P3.1, Serial Port 1 on P1.2/P1.3), a programmable watchdog timer, early-warning power-fail interrupt (PFI), and configurable timer clocking via CKCON register (8Eh) - allowing timers to run at either 4- or 12-clock-per-cycle modes independently for backward timing compatibility or enhanced resolution.

Key Specifications

Pinout & Package

DS80C320-FCG+ is housed in a 40-pin hermetically sealed ceramic DIP (CERDIP) package with 0.6-inch width, rated for -40°C to +85°C industrial temperature range and RoHS-compliant lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-MNG+, the DS80C320-FCG+ provides superior long-term reliability in humid or thermally cycling environments due to its ceramic package; compared with DS80C323-QNL+, it delivers higher deterministic throughput for time-critical control loops but requires stable 5V supply and board space for CERDIP footprint.

Availability

DS80C320-FCG+ is available at Aetrix Electronics and suitable for industrial control panels, medical device subsystems, and smart metering gateways requiring stable component supply across 10+ year production lifecycles.

Supply support for DS80C320-FCG+ 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 high-performance analog, mixed-signal, and embedded processing solutions for industrial, automotive, and communications markets.

The DS80C320-FCG+ 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, reliability, and feature upgrades without architectural disruption.

FAQ

What is the maximum crystal frequency supported by DS80C320-FCG+?

The DS80C320-FCG+ supports a maximum crystal frequency of 33MHz, enabling an effective instruction execution rate of approximately 82.5MHz due to its 4-clock-per-machine-cycle architecture. This specification is validated in the official Maxim datasheet Rev 101006, Section "ORDERING INFORMATION", where DS80C320-FCG+ is explicitly listed under the 33MHz speed grade. Operating beyond 33MHz violates absolute maximum ratings and may cause timing violations or functional failure.

Does DS80C320-FCG+ require external pull-up resistors on Port 0?

Yes, DS80C320-FCG+ requires external pull-up resistors on Port 0 (P0.0–P0.7) when used as a general-purpose I/O or during external memory read cycles. Unlike Ports 1–3, Port 0 has no internal pull-ups and functions as an open-drain bus during ALE-low phases. The official datasheet Section "PIN DESCRIPTION" confirms this behavior and recommends 4.7kΩ resistors for reliable TTL-level signaling in standard 5V systems.

How does the dual data pointer in DS80C320-FCG+ improve memory transfer efficiency?

The DS80C320-FCG+ implements two independent 16-bit data pointers (DPTR0 at SFR 82h/83h, DPTR1 at 84h/85h) selectable via DPS bit (SFR 86h). This eliminates software overhead of saving/restoring addresses during block moves - a 64-byte transfer executes in 1097 machine cycles versus 1869 with single DPTR, saving 123.5μs at 25MHz. This is documented in the "DUAL DATA POINTER" section (Page 13) with verified assembly code comparison.

Is DS80C320-FCG+ pin-compatible with standard 80C32 devices?

Yes, DS80C320-FCG+ is fully pin-compatible with 80C32 devices in the 40-pin DIP package, sharing identical pin functions for VCC, GND, RST, XTAL1/XTAL2, P0–P3, EA, PSEN, ALE, RD, and WR. The datasheet Section "80C32 COMPATIBILITY" explicitly states drop-in replacement capability, though designers must verify timing margins for external memory due to faster core execution - especially with legacy 120ns SRAM.

What is the function of the CKCON register in DS80C320-FCG+?

The CKCON register (SFR 8Eh) in DS80C320-FCG+ controls two critical timing parameters: bits CKCON.2–0 configure MOVX instruction strobe width (2–9 machine cycles) for interfacing mixed-speed peripherals, while CKCON.3–5 independently select 4- or 12-clock-per-cycle operation for Timers 0–2. This allows legacy timing compatibility on reset (12-clock default) while enabling higher-resolution timing when needed - detailed in Section "STRETCH MEMORY CYCLE" and "TIMER-RATE CONTROL".