Intel PC28F640P33B85D: A Comprehensive Technical Overview of the 64-Mbit Parallel NOR Flash Memory
The Intel PC28F640P33B85D represents a significant component within the realm of non-volatile memory solutions, embodying the robust performance and reliability characteristic of Intel's parallel NOR Flash technology. This 64-Mbit (8-MByte) memory device is engineered for applications demanding high-speed read operations, exceptional data integrity, and seamless in-system execution, often serving as a critical boot medium in embedded systems, networking equipment, and industrial controls.
Architecturally, the device is organized as 8,388,608 words x 8 bits or 4,194,304 words x 16 bits, providing design flexibility for both 8-bit and 16-bit microprocessor buses. This organization is pivotal for enabling efficient memory access and is a hallmark of parallel NOR Flash, which offers a full memory-mapped interface and random access capabilities. This allows for direct code execution (XIP - eXecute In Place), eliminating the need to shadow code into RAM and thus simplifying system architecture and reducing boot times.
A core feature of this memory is its asynchronous page mode operation. This mode significantly enhances effective read performance by allowing rapid access to data within a selected "page" of memory, achieving page access times as low as 25ns. This makes it well-suited for high-performance computing environments where throughput is critical. The device operates on a single 3.3V V~CC~ supply, aligning with modern low-voltage power requirements and contributing to lower overall system power consumption.
The PC28F640P33B85D is built on Intel's advanced 0.13μm MirrorBit® process technology. This proprietary technology effectively doubles the intrinsic density of the Flash memory cell by storing a charge on an insulating nitride layer instead of a traditional floating gate. The benefits are multifold: it enables higher densities, improves reliability, and provides superior endurance compared to earlier NOR Flash architectures. The device boasts a minimum of 100,000 program/erase cycles per sector, ensuring longevity and durability for frequently updated firmware.
Data integrity is further safeguarded by sophisticated command set functionality and hardware protection features. The device is controlled through a standardized write state machine, which automates the complex algorithms for programming and erasure, reducing the burden on the host processor. Key protection mechanisms include a volatile and non-volatile block locking scheme to prevent accidental writes or erasures to critical boot code sectors, and a 64-bit Protection Register for storing unique, factory-programmed or user-defined security identifiers.
From a packaging and reliability perspective, the "D" suffix in its part number denotes a TSOP (Thin Small Outline Package) offering, which is a space-efficient and robust form factor suitable for automated assembly processes. The device is specified to operate over the industrial temperature range of -40°C to +85°C, ensuring stable performance in harsh environmental conditions.
ICGOOODFIND: The Intel PC28F640P33B85D stands as a quintessential solution for systems requiring reliable, high-speed, non-volatile storage with instant-on capabilities. Its combination of a mature parallel interface, robust process technology, and comprehensive hardware protection makes it a enduringly relevant choice for mission-critical embedded designs.
Keywords: Parallel NOR Flash, Execute In Place (XIP), MirrorBit® Process, Asynchronous Page Mode, Block Locking Protection.
