Intel RC28F256J3C-125: A 125ns 32Mb Parallel NOR Flash Memory for Embedded Systems

In the realm of embedded systems, where reliability, deterministic performance, and direct code execution are paramount, parallel NOR Flash memory remains a foundational technology. The Intel RC28F256J3C-125 stands as a classic and robust example of this memory type, engineered to meet the stringent demands of industrial, automotive, and networking applications.

This device is a 32-megabit (4MB) CMOS NOR Flash memory, organized as 256K words of 16 bits each. Its core strength lies in its parallel interface, which provides a direct connection to a microcontroller's address and data buses. This architecture is crucial for eXecute-In-Place (XIP) functionality, allowing the host processor to run code directly from the flash memory without the need to first copy it to RAM. This capability significantly simplifies system design and reduces boot times.

A key specification highlighted in its part number is its 125ns maximum access time. This swift and predictable read performance ensures that even high-speed processors can interface with it with minimal wait states, guaranteeing consistent and reliable system operation. The device operates on a single 4.5V to 5.5V supply voltage, a common standard for legacy and industrial systems.

Beyond its read performance, the RC28F256J3C-125 offers a full suite of features for in-system manageability. It supports block locking for software and data protection, allowing specific memory sectors to be write-protected to prevent accidental corruption or unauthorized access. Programming and erase operations are managed through a command-set interface, standard for JEDEC-compatible flash memories, making it easy to integrate into existing firmware routines.

While newer serial memories like SPI NOR offer smaller packages, the parallel interface of this Intel memory provides an unbeatable high-bandwidth data path, making it ideal for systems where performance cannot be compromised. Its durability is characterized by a minimum 100,000 program/erase cycles per sector and extensive data retention, ensuring data integrity over the long operational life of an embedded product.

ICGOODFIND Summary: The Intel RC28F256J3C-125 is a high-performance, reliable parallel NOR Flash solution. Its fast 125ns access time, XIP capability, and robust sector protection features make it an excellent, albeit legacy, choice for mission-critical embedded systems requiring deterministic boot-up and execution directly from flash.

Keywords: Parallel NOR Flash, Execute-In-Place (XIP), 125ns Access Time, Embedded Systems, Block Locking.