Analog Devices Inc./Maxim Integrated DS80C320-QCL/T&R

Overview

DS80C320-QCL/T&R from Maxim Integrated is a high-speed, 80C32-compatible 8-bit microcontroller featuring a 4-clock-per-machine-cycle core, 33MHz maximum crystal frequency, 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 and targets legacy 8051 system upgrades requiring deterministic real-time control in industrial instrumentation and embedded communications.

For engineers reviewing the DS80C320-QCL/T&R datasheet, DS80C320-QCL/T&R pinout, DS80C320-QCL/T&R application, or DS80C320-QCL/T&R equivalent, this page delivers verified electrical parameters, validated PLCC-44 pin mapping, confirmed dual-DPTR memory move acceleration, stretchable MOVX timing control, and drop-in replacement guidance for 80C32-based designs operating at 0°C to +70°C.

Technical Context

The DS80C320-QCL/T&R implements a redesigned 8051-compatible core eliminating wasted clock cycles - executing most instructions in 4 oscillator cycles versus 12 in standard 80C32, yielding up to 3× faster execution at identical crystal frequencies. Its architecture retains full instruction set compatibility while introducing new SFRs (e.g., CKCON at 8Eh) for configurable MOVX stretch (2–9 machine cycles) and timer speed selection (4/12 clocks per increment).

It integrates two independent UARTs (Serial Port 0 on P3.0/P3.1; Serial Port 1 on P1.2/P1.3), seven external interrupts (INT2–INT5 added beyond INT0/INT1), programmable watchdog timer, early-warning power-fail interrupt, and dual data pointers (DPTR0 at 82h/83h, DPTR1 at 84h/85h) with DPS bit at 86h - all accessible without altering existing 80C32 software flow except for timing-critical loops.

Key Specifications

Pinout & Package

DS80C320-QCL/T&R is housed in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead geometry, RoHS-compliant, rated for 0°C to +70°C operation. Pin 1 is located at the index corner adjacent to the notch; pins are numbered counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with DS80C320-QCL/T&R, DS80C320-QNG+ offers extended temperature resilience without sacrificing speed or pin compatibility, while DS80C323-QCL+ trades clock rate and voltage headroom for broader supply adaptability - neither is pin-compatible with non-PLCC variants, and both require validation of MOVX timing and interrupt vector mapping in target firmware.

Availability

DS80C320-QCL/T&R is available at Aetrix Electronics and suitable for industrial PLC I/O modules, legacy 8051 system upgrades, multi-protocol communication gateways, embedded test equipment controllers, and medical device firmware requiring stable component supply across long production lifecycles.

Supply support for DS80C320-QCL/T&R 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 design house specializing in precision analog, mixed-signal, and high-reliability microcontrollers for industrial, medical, and communications infrastructure.

The DS80C320-QCL/T&R belongs to Maxim's high-speed 8051-compatible microcontroller family, engineered to deliver deterministic real-time performance and seamless migration paths for legacy 5V embedded systems without architectural overhaul.

FAQ

Is DS80C320-QCL/T&R pin-compatible with standard 80C32 devices in PLCC-44 packages?

Yes, DS80C320-QCL/T&R is fully pin-compatible with 80C32 devices in 44-pin PLCC packages, including identical signal assignments for P0–P3, RST, XTAL1/XTAL2, EA, and VCC/GND. All standard 80C32 peripheral functions - timers, serial port 0, and interrupts - map to the same pins. DS80C320-QCL/T&R adds new functions (e.g., RXD1/TXD1 on P1.2/P1.3, INT2–INT5 on P1.4–P1.7) on previously unused PLCC pins, preserving backward compatibility while expanding capability without PCB changes.

What is the default MOVX timing behavior of DS80C320-QCL/T&R after reset?

After reset, DS80C320-QCL/T&R configures MOVX timing to a 3-machine-cycle default (CKCON.2–0 = 001), producing a 4-clock RD/WR strobe width - compatible with common 120ns–150ns SRAMs. This avoids requiring faster memory in legacy designs. To achieve minimum 2-cycle MOVX, software must write 000b to CKCON bits 2–0; to extend to 9 cycles for slow peripherals, write 111b. The DS80C320-QCL/T&R does not auto-adjust MOVX timing - explicit SFR writes are required.

Does DS80C320-QCL/T&R support both Timer 1 and Timer 2 for baud rate generation on Serial Port 1?

No, DS80C320-QCL/T&R supports Timer 1 only for baud rate generation on Serial Port 1 (SP1). Serial Port 0 (SP0) can use either Timer 1 or Timer 2, as in standard 80C32. SP1's baud rate control register (TCLK1 in SCON1) lacks Timer 2 selection bits - its timing is exclusively derived from Timer 1 overflow. This constraint requires careful allocation of Timer 1 when both UARTs operate simultaneously at different baud rates, as SP1 cannot offload timing to Timer 2 like SP0 can.

How does the dual data pointer (DPTR0/DPTR1) in DS80C320-QCL/T&R accelerate memory block transfers?

The DS80C320-QCL/T&R dual data pointer accelerates memory block transfers by eliminating address reload overhead: DPTR0 (82h/83h) and DPTR1 (84h/85h) are independently loaded, and the DPS bit (bit 0 of 86h) selects which is active for MOVX instructions. A 64-byte block move using dual DPTR saves 772 machine cycles versus single-DPTR code at 25MHz - reducing execution time from 299μs to 175.5μs. This is achieved by toggling DPS instead of saving/restoring addresses in registers, directly improving memcpy() and DMA-like routines in resource-constrained firmware.

Can DS80C320-QCL/T&R operate reliably with a 33MHz crystal while maintaining full 8051 instruction set compatibility?

Yes, DS80C320-QCL/T&R executes the complete 8051 instruction set with identical functional results as standard 80C32, but at accelerated speeds: most instructions run in 4 oscillator cycles (vs. 12), delivering up to 3× throughput at 33MHz. Instruction effects on flags, registers, and memory remain byte-identical - only timing differs. Critical real-time functions (e.g., timer-based baud rates) default to 12-clock mode post-reset for compatibility; software must explicitly configure CKCON bits to enable 4-clock timer operation. Thus, 33MHz operation is fully supported and preserves software correctness.