Intel JS28F640J3D-75: A Detailed Overview of the 64-Megabit Flash Memory Device
The Intel JS28F640J3D-75 is a prominent 64-megabit (8-megabyte) NOR Flash memory device that has been a cornerstone in embedded systems design. Manufactured on Intel's advanced 0.13-micron MirrorBit process technology, this component represents a significant achievement in non-volatile memory, balancing density, performance, and reliability for a wide array of applications.
Architecture and Core Features
This device is organized as 8,388,608 words of 8 bits each or 4,194,304 words of 16 bits each, providing designers with flexibility for different system bus widths. A key architectural highlight is its uniform 128-Kbyte block structure. Each block can be erased independently, allowing for efficient memory management where specific sectors can be updated without affecting others. This is crucial for storing application code, boot code, and configuration data simultaneously.
The "-75" suffix in its part number denotes a maximum initial access time of 75ns, making it suitable for systems requiring reliable, direct code execution from Flash (XiP - eXecute in Place) without the need to first shadow code into faster RAM.
Advanced Functionality and Performance
Beyond basic read and write operations, the JS28F640J3D-75 incorporates several advanced features that were cutting-edge for its time. It supports a 1.8V VCC supply voltage for core logic operations, significantly reducing power consumption compared to older 3.3V devices. For I/O compatibility with higher voltage systems, it features a separate 3V VIO supply.
The device operates with a sophisticated command-set interface, which is used to initiate operations like programming (writing) and block erasure. This interface protects the memory from accidental writes. Furthermore, it supports features like Write Protection through block locking, where specific memory blocks can be hardened against modification to protect critical boot code.
Reliability and Endurance
Built for industrial and demanding commercial applications, this Flash memory device boasts impressive endurance and data retention specifications. It is rated for a minimum of 100,000 program/erase cycles per block, ensuring it can handle frequent firmware updates over the product's lifetime. Data integrity is maintained for up to 20 years, guaranteeing that information remains intact long after being written.
Target Applications
The combination of density, speed, and reliability made the Intel JS28F640J3D-75 a popular choice across numerous industries. Its primary applications include:
Telecommunications Equipment: For storing firmware and configuration data in routers, switches, and base stations.
Automotive Systems: In engine control units (ECUs) and infotainment systems where temperature robustness and long-term data retention are critical.
Industrial Control Systems: Programmable Logic Controllers (PLCs) and other factory automation hardware.
Consumer Electronics: Set-top boxes, printers, and networking devices.
ICGOOODFIND
The Intel JS28F640J3D-75 stands as a testament to a pivotal era in Flash memory development. Its robust architecture, featuring advanced process technology, low-voltage operation, and a highly reliable block-erase design, established a high benchmark for performance and integration in 64-megabit NOR Flash devices. It provided a critical foundation for the embedded systems that powered the technological evolution of the 2000s and beyond.
Keywords:
1. NOR Flash Memory
2. Non-Volatile Storage
3. Execute-in-Place (XiP)
4. Block Erase Architecture
5. Program/Erase Endurance
