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Analog Devices Inc./Maxim Integrated DS89C440-ENL
- Part No.:
- DS89C440-ENL
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Microcontrollers
- Package:
- 44-TQFP
- Datasheet:
-
DS89C440-ENL.pdf
- Description:
- IC MCU 8BIT 32KB FLASH 44TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:4,551
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Product details
Overview
DS89C440-ENL from Maxim Integrated (now part of Analog Devices) is a discontinued 8051-compatible ultra-high-speed flash microcontroller with 32kB on-chip flash memory, 1kB MOVX SRAM, and 44-pin TQFP package. It executes instructions at one clock per machine cycle, achieves up to 33 MIPS at 33MHz, and supports dual serial ports, five interrupt priority levels, and programmable power management for industrial control and data logging applications.
For engineers reviewing the DS89C440-ENL datasheet, DS89C440-ENL pinout, DS89C440-ENL application, or DS89C440-ENL equivalent, key selection considerations include its 32kB flash size (distinct from 16kB DS89C430 and 64kB DS89C450), TQFP-44 package compatibility, 33MHz max clock, dual UART support, and legacy 8051 instruction set with accelerated timing.
Technical Context
The DS89C440-ENL implements a fully static, one-clock-per-cycle 8051 core-eliminating the traditional 12-clock-per-cycle bottleneck-enabling 12× faster instruction execution than standard 8051s at identical crystal frequencies. Its architecture includes dual data pointers with automatic increment/decrement, four paged memory-access modes, and ROMSIZE configuration for dynamic internal memory mapping.
It integrates a programmable clock divider (1× to 1024×), EMI-reduction mode (ALE disable during idle external memory access), early-warning power-fail interrupt, and hardware watchdog timer. The device operates across –40°C to +85°C with 4.5V–5.5V supply and supports in-system programming via serial port using ROM-resident loader.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | One-clock-per-cycle 8051-compatible CPU - eliminates wasted cycles, enabling true 33 MIPS at 33MHz. |
| Flash Memory | 32kB on-chip flash - supports in-application reprogramming and retains data for 100 years. |
| SRAM | 1kB MOVX SRAM - dedicated fast RAM accessible via MOVX instructions, separate from 256B internal RAM. |
| Max Clock Frequency | 33MHz system clock - supports external crystal (1–33MHz) or external clock source with configurable multipliers. |
| I/O Ports | Four 8-bit bidirectional ports (P0–P3) - P0 functions as multiplexed address/data bus; P1/P2/P3 support alternate functions including dual UART, seven external interrupts, and timer I/O. |
| Power Management | Programmable clock divider (1× to 1024×) with automatic hardware/software exit - reduces active current to 1–100µA in stop mode (bandgap disabled). |
| Operating Voltage | 4.5V to 5.5V - compatible with standard 5V industrial logic; includes power-fail warning (VPFW = 4.2–4.6V) and reset trip point (VRST = 3.95–4.35V). |
Pinout & Package
DS89C440-ENL is housed in a 44-pin Thin Quad Flat Package (TQFP) with 0.8mm lead pitch, RoHS-compliant, and thermally enhanced for industrial ambient operation (–40°C to +85°C). Pinout conforms to standard 8051 layout with extended functionality mapped to Port 1 (T2, RXD1/TXD1, INT2–INT5) and Port 3 (RXD0/TXD0, RD/WR, INT0/INT1).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC (Pins 16,17,28,39) | Power Supply | +5V main supply; four pins reduce IR drop and improve noise immunity in high-speed operation. |
| GND (Pins 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,18,19,20,21,22,23,24,25,26,27,29,30,31,32,33,34,35,36,37,38,40,41,42,43,44) | Ground Reference | Multiple ground connections minimize ground bounce and stabilize timing margins at 33MHz. |
| RST (Pin 4) | Reset Input/Output | Bidirectional Schmitt-trigger input with internal 50–200kΩ pulldown - enables wire-OR reset sources without external RC network. |
| XTAL1 (Pin 14), XTAL2 (Pin 15) | Clock Interface | Crystal oscillator inputs supporting fundamental-mode AT-cut crystals (1–33MHz); XTAL1 accepts external clock source. |
| P0.0–P0.7 (Pins 33–37,32,31,30) | Multiplexed Address/Data Bus | Open-drain port with weak pullups - provides AD0–AD7 during ALE high; transitions to bidirectional data bus when ALE low. |
| P2.0–P2.7 (Pins 18–25) | High-Order Address Bus | Provides A8–A15 for external memory access; supports page mode addressing with dynamic LSB/MSB roles. |
| P3.6 (Pin 12), P3.7 (Pin 13) | Memory Strobes | WR and RD signals - active-low strobes synchronized to ALE for precise external RAM/peripheral timing. |
| EA (Pin 29) | External Access Control | Logic-high selects internal 32kB flash; logic-low forces external program memory fetch - enables hybrid memory configurations. |
Key Features
| Feature | Design Value |
|---|---|
| Dual Full-Duplex UARTs | Serial Port 0 (P3.0/P3.1) and Serial Port 1 (P1.2/P1.3) - enable simultaneous host communication and peripheral bridging without software bit-banging. |
| Seven External Interrupt Sources | INT0–INT5 plus power-fail interrupt - supports real-time event handling with five priority levels for deterministic response in motor control or safety systems. |
| Variable-Length MOVX Timing | Configurable MD2:MD0 bits add 2–9 machine cycles to MOVX - accommodates slow peripherals (e.g., legacy ADCs or EEPROMs) without firmware wait-state insertion. |
| EMI Reduction Mode | Disables ALE during non-memory-access cycles - lowers radiated emissions in building automation or medical devices meeting CISPR 22 Class B. |
| ROMSIZE Configuration | Software-selectable internal program memory size (0–32kB) - allows dynamic remapping of external memory space while retaining bootloader in protected flash region. |
| Power-Fail Early Warning | VPFW threshold (4.2–4.6V) triggers interrupt before VRST (3.95–4.35V) - enables graceful shutdown, data save, or UPS handoff in uninterruptible power supplies. |
Applications
| Data Logging Systems | Industrial HVAC Controllers |
|---|---|
Use Scenario: Standalone environmental sensor node recording temperature, humidity, and airflow at 10Hz with local flash storage and RS-485 upload. IC Role / Device Role / Timing Role: Primary controller executing real-time sampling, timestamping, and protocol stack; uses dual UARTs for sensor interface and master communication. Use Value: 32kB flash stores >72 hours of 10Hz data; 33MHz core processes CRC and compression in <1ms; power-fail interrupt preserves last valid reading during brownout. |
Use Scenario: Zone-level HVAC unit managing fan speed, damper position, and refrigerant valves via PWM and analog outputs under ASHRAE 135 BACnet MS/TP. IC Role / Device Role / Timing Role: Real-time motion control engine coordinating multiple PID loops; uses Timer 2 capture for tachometer feedback and INT2–INT5 for fault inputs. Use Value: One-clock-per-cycle execution ensures sub-100µs loop jitter; dual DPTRs accelerate buffer transfers between sensor FIFOs and BACnet packet assembly. |
| White Goods Motor Control | Building Security Panels |
Use Scenario: Washing machine main board driving BLDC motor, water valves, and user interface with vibration sensing and load balancing. IC Role / Device Role / Timing Role: Central MCU managing commutation timing, current sensing, and safety interlocks; uses P1.0/T2 and P1.1/T2EX for precise hall-effect timing capture. Use Value: 33MHz clock enables 20kHz PWM carrier with 12-bit resolution; programmable watchdog prevents runaway motor conditions; EMI reduction meets IEC 61000-4-3. |
Use Scenario: Access control panel authenticating RFID cards, managing door strikes, monitoring tamper switches, and reporting over TCP/IP via Ethernet PHY. IC Role / Device Role / Timing Role: Protocol gateway translating Wiegand/RS-485 to TCP; uses Serial Port 1 for reader interface and Serial Port 0 for PHY UART bridge. Use Value: 32kB flash hosts dual firmware images (active/backup); ROMSIZE allows secure bootloader isolation; power-fail interrupt logs last access event before backup battery depletion. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8051-compatible microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS89C430-ENL | 16kB flash, same 44-TQFP package, identical pinout and peripheral set - differs only in flash capacity and ROMSIZE range. | Suitable where firmware image size ≤16kB; lower cost but requires external memory for larger applications. | Select when design constraints allow reduced code footprint and cost sensitivity outweighs future upgrade headroom. |
| DS89C450-ENL | 64kB flash, same 44-TQFP package and full feature parity - direct functional superset with expanded memory mapping. | Required for complex protocol stacks (e.g., Modbus TCP, DALI) or field-upgradable firmware with dual-bank capability. | Preferred for new designs needing long-term scalability; pin-compatible drop-in replacement per Maxim documentation. |
Compared with DS89C440-ENL, DS89C430-ENL offers lower memory capacity at reduced cost but identical speed and peripherals, while DS89C450-ENL provides 2× more flash and broader ROMSIZE flexibility-making it the recommended path for production continuity given DS89C440-ENL's discontinuation status.
Availability
DS89C440-ENL is available at Aetrix Electronics and suitable for industrial control, building energy management, and data logging applications requiring stable component supply despite its discontinued status through verified legacy channel inventory and cross-qualified alternatives.
Supply support for DS89C440-ENL 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 (acquired by Analog Devices in 2021) is a semiconductor company specializing in high-performance analog, mixed-signal, and embedded processing solutions for industrial, automotive, and communications markets.
The DS89C440-ENL belongs to Maxim's Ultra-High-Speed Flash Microcontroller family, designed to deliver 12× 8051 performance while maintaining full software and pin compatibility-targeting legacy 8051 upgrades in cost-sensitive, reliability-critical industrial systems.
FAQ
Is DS89C440-ENL still in production?
No, DS89C440-ENL is discontinued per Maxim's ordering information, which states "DS89C440-xxx Contact factory or replace with DS89C430 or DS89C450." Aetrix Electronics sources remaining factory inventory and qualified second-source stock with full traceability, but long-term designs should migrate to DS89C450-ENL for identical pinout and enhanced 64kB flash.
What is the correct replacement for DS89C440-ENL in a PCB layout?
The DS89C450-ENL is the documented drop-in replacement for DS89C440-ENL, sharing identical 44-TQFP package, pinout, voltage ratings, and AC timing. No PCB changes are required; only firmware adjustments may be needed to utilize the additional 32kB flash and extended ROMSIZE configuration range supported by DS89C450-ENL.
Does DS89C440-ENL support in-system programming (ISP)?
Yes, DS89C440-ENL supports in-system programming via its primary UART (P3.0/P3.1) using the ROM-resident bootloader. The device requires no external programming hardware-only a serial connection and host-side loader software compliant with Maxim's serial programming protocol defined in the Ultra-High-Speed Flash Microcontroller User's Guide.
What are the key timing differences between DS89C440-ENL and standard 8051 MCUs?
DS89C440-ENL executes all instructions in one clock cycle versus 12 cycles in standard 8051s-reducing instruction time from ~1.2μs (at 1MHz) to 30ns (at 33MHz). Critical timing parameters like ALE pulse width, MOVX setup/hold, and serial port clocking scale linearly with system clock, requiring firmware review for legacy 8051 timing-critical routines.
Can DS89C440-ENL operate with a 3.3V supply?
No, DS89C440-ENL is specified only for 4.5V–5.5V operation per Absolute Maximum Ratings and DC Electrical Characteristics. Its VIH thresholds (≥2.0V), VOL (≤0.45V), and internal regulators require 5V nominal supply; interfacing with 3.3V peripherals necessitates level-shifting on all I/O lines, including UART and address/data buses.
DS89C440-ENL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 44-TQFP
- Series:
- 89C
- Packaging:
- Bag
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Core Processor:
- 8051
- Core Size:
- 8-Bit
- Speed:
- 33MHz
- Connectivity:
- EBI/EMI, SIO, UART/USART
- Peripherals:
- Power-Fail Reset, WDT
- Number of I/O:
- 32
- Program Memory Size:
- 32KB (32K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 1K x 8
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- External
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
DS89C440-ENL FAQ
1.How can I place an order for DS89C440-ENL through Aetrix?
Please submit a Request for Quotation (RFQ) for DS89C440-ENL on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for DS89C440-ENL reliable?
The price and inventory of DS89C440-ENL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS89C440-ENL is usually 5 days.
3.What payment methods are accepted for DS89C440-ENL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS89C440-ENL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS89C440-ENL?
DS89C440-ENL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS89C440-ENL order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for DS89C440-ENL?
For technical support, including DS89C440-ENL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS89C440-ENL requirements.
6.How does Aetrix verify that DS89C440-ENL is sourced from the original manufacturer or authorized distributors?
All DS89C440-ENL products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that DS89C440-ENL meets industry standards.
7.What is the process for return or replacement of DS89C440-ENL?
All DS89C440-ENL units undergo pre-shipment inspection (PSI). If there is an issue with DS89C440-ENL, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The DS89C440-ENL part is unused and in its original packaging.
Return procedure for DS89C440-ENL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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