Analog Devices Inc./Maxim Integrated DS80C320-QNG

Overview

DS80C320-QNG 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 full-duplex hardware serial ports. It operates from 4.25V to 5.5V at up to 25MHz (–40°C to +85°C), delivering ~2.5× speed improvement over standard 80C32 in real-world code-ideal for industrial control upgrades requiring deterministic timing and legacy 8051 software compatibility.

For engineers reviewing the DS80C320-QNG datasheet, DS80C320-QNG pinout, DS80C320-QNG application, or DS80C320-QNG equivalent, key selection considerations include its PLCC-44 package, programmable MOVX memory access stretch (2–9 cycles), dual data pointer for accelerated block moves, power-fail reset/interrupt, and watchdog timer-features critical for robust embedded systems where reliability, timing predictability, and drop-in 80C32 replacement are required.

Technical Context

The DS80C320-QNG implements a redesigned 8051 core eliminating wasted clock cycles: all instructions execute in 4–28 oscillator cycles (vs. 12–48 in legacy 80C32), with 159 opcodes achieving 3× speedup. Its dual-data-pointer architecture (DPTR0 at 82h/83h, DPTR1 at 84h/85h, selected via DPS bit at 86h) enables single-instruction pointer switching during memory block transfers.

Peripheral timing is decoupled from CPU speed: timers default to 12-clock-per-cycle operation post-reset for backward baud rate compatibility, but CKCON register (8Eh) allows per-timer reconfiguration to 4-clock mode. MOVX access timing is independently adjustable via CKCON[2:0], supporting mixed-speed memory/peripherals without glue logic.

Key Specifications

Pinout & Package

DS80C320-QNG is housed in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead configuration, compatible with standard PLCC-44 sockets and reflow soldering profiles. Pin 1 is marked by a notch on the top-left corner when viewed from above with the notch oriented left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-QNG, DS80C320-QCL offers higher clock headroom at the cost of stricter timing validation, while DS80C323-QND trades speed for wider voltage range-making DS80C320-QNG the optimal balance of performance, ruggedness, and drop-in compatibility for industrial 5V systems.

Availability

DS80C320-QNG is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy equipment controller upgrades, energy meter communication hubs, and smart building BACnet gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for DS80C320-QNG 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 semiconductor solutions for industrial, medical, and communications markets.

The DS80C320-QNG belongs to Maxim's high-speed 8051 microcontroller family, engineered specifically to deliver deterministic real-time performance and seamless migration paths for legacy 80C32-based systems in harsh environments.

FAQ

What is the maximum operating frequency of the DS80C320-QNG?

The DS80C320-QNG is rated for a maximum crystal frequency of 25MHz across its full operating temperature range of –40°C to +85°C. This yields an effective instruction throughput of approximately 82.5 million instructions per second (MIPS) due to its 4-clock-per-cycle architecture. The DS80C320-QNG datasheet specifies this limit under worst-case voltage (4.25V) and temperature conditions, ensuring reliable timing margin for industrial applications.

Does the DS80C320-QNG include on-chip flash or ROM memory?

No, the DS80C320-QNG does not contain any on-chip program memory (ROM or flash). It is a ROMless variant that relies entirely on external program memory accessed via the multiplexed P0 address/data bus and P2 address bus. The DS80C320-QNG does include 256 bytes of on-chip scratchpad RAM. External program memory is enabled by tying the EA pin (Pin 35) low, as confirmed in the DS80C320-QNG pin description and ordering information tables.

How does the dual data pointer in the DS80C320-QNG improve memory transfer performance?

The DS80C320-QNG implements two independent 16-bit data pointers (DPTR0 at SFR 82h/83h and DPTR1 at 84h/85h), selected via the DPS bit (bit 0 of SFR 86h). This allows the DS80C320-QNG to maintain separate source and destination addresses during block memory moves without software-managed register saves. As demonstrated in the DS80C320-QNG user guide, a 64-byte move executes in 1097 machine cycles instead of 1869-reducing execution time by 42% and eliminating 12 cycles per loop iteration compared to single-DPTR implementations.

Can the DS80C320-QNG replace a standard 80C32 in an existing design without hardware changes?

Yes, the DS80C320-QNG is pin-compatible and instruction-set-compatible with the standard 80C32 in the same PLCC-44 package, making it a drop-in replacement for most designs. However, engineers must verify external memory timing-faster execution may require faster RAM or adjustment of MOVX stretch settings (CKCON[2:0]). Also, the DS80C320-QNG's power-fail reset and watchdog features require connecting VCC monitoring and WDI/WDO pins per the DS80C320-QNG datasheet, which are not present on legacy 80C32 devices.

What is the function of the MOVX stretch feature in the DS80C320-QNG?

MOVX stretch in the DS80C320-QNG controls the number of machine cycles used for external data memory read/write operations, configurable from 2 to 9 cycles via bits CKCON[2:0]. This allows the DS80C320-QNG to interface directly with both fast SRAM (e.g., 120ns) and slow peripherals (e.g., LCD controllers) without external wait-state logic. On reset, the DS80C320-QNG defaults to 3-cycle MOVX (CKCON = 0x02), providing backward compatibility with existing 80C32 memory subsystems while enabling optimization for specific external devices.