Intel RC28F256J3F95A: Technical Specifications and Application Analysis for a 3V 32Mbit Parallel NOR Flash Memory
In the realm of embedded systems and legacy computing, parallel NOR Flash memory remains a cornerstone technology for applications requiring reliable, non-volatile storage with high-speed read access. The Intel RC28F256J3F95A is a classic example of this memory type, offering a robust combination of performance and density. This article delves into its technical specifications and explores its typical application scenarios.
Technical Specifications Deep Dive
The RC28F256J3F95A is a 3.0-volt (3V) single power supply memory device, organized as 32 Megabits (4 Megabytes). Its parallel interface, a defining characteristic, provides a 16-bit wide data bus, enabling efficient data transfer for 8-bit or 16-bit microprocessors. This architecture allows for execute-in-place (XIP) capabilities, where code can be run directly from the flash memory without the need to first copy it to RAM, significantly simplifying system design.
A key feature of this memory is its asynchronous page mode access. By accessing data within the same "page" of memory, it can achieve faster read cycle times, with a page mode read time of 25ns compared to its standard access time of 95ns. This feature is critical for improving overall system throughput.
The device is built on Intel's proven 0.13μm mirrorBit™ process technology, which provides the foundation for its reliability and density. It offers a minimum of 100,000 program/erase cycles per sector, ensuring longevity for firmware that requires periodic updates. Furthermore, its data retention is rated at 20 years, guaranteeing the integrity of stored code over the lifespan of the end product.
For in-system manageability, the chip complies with the Common Flash Memory Interface (CFI), which allows host software to automatically query the device to determine its vendor, density, and electrical parameters. This simplifies system integration and firmware design.
Application Analysis
The primary strength of the RC28F256J3F95A lies in its use as firmware storage and code shadowing in various embedded systems. Its XIP capability makes it ideal for:
Networking Equipment: Used in routers, switches, and hubs to store bootloaders and operating system kernels that require immediate execution upon power-up.
Industrial Control Systems (ICS): Employed in programmable logic controllers (PLCs) and robotics where reliable, long-term storage of control firmware is paramount. Its wide temperature range and endurance make it suitable for harsh environments.
Telecommunications Infrastructure: Found in base stations and communication controllers for holding critical initialization code.
Legacy and Upgraded Systems: Serves as a direct replacement or upgrade path for older NOR flash devices in existing designs, thanks to its standard pinout and interface.
While newer serial flash memories (like SPI NOR) offer smaller packages and lower pin counts, the parallel NOR Flash, exemplified by the RC28F256J3F95A, retains its advantage in raw read performance and deterministic read timing, which is often crucial during the initial boot process of a system.
The Intel RC28F256J3F95A represents a mature, high-performance solution for systems demanding robust, non-volatile storage with fast read access. Its 3V operation, 32Mbit density, and parallel interface make it a steadfast component in networking, industrial, and telecommunications applications where reliability and direct code execution are critical. Despite the trend towards serial interfaces, its performance profile ensures its relevance in specific market segments.
Keywords:
1. Parallel NOR Flash
2. Execute-in-Place (XIP)
3. Firmware Storage
4. Asynchronous Page Mode
5. Common Flash Interface (CFI)
