Serial Flash Chip Offers More for Less

By Susan Hospod
iApplianceWeb
(12/21/01, 09:55:54 AM EDT)

STMicroelectronics has introduced a 2-Mbit serial flash memory chip, which provides very fast access and user-friendliness for advanced applications.

The M25P20 operates from a single 2.7V to 3.6V supply voltage, enabling storage of both data and programs. Plus it can be read, programmed, and erased faster than its predecessors. This device features sequential and random read operation, page mode programming, sector and bulk erase modes, and a 25MHz SPI-compatible serial bus.

As a result, the M25P20 is suitable for a wide variety of computer applications, such as printers, hard-disk drives, graphic cards, add-on cards, and consumer applications, including digital set-top boxes, home appliances, embedded Web servers, and digital still cameras. Other applications include automotive and telecom devices and industrial and medical equipment.

The M25P20 contains four sectors of 256 pages each. The memory's page program instruction writes one to 256 bytes at a time. The entire memory can be erased at once using a bulk erase instruction. Alternatively, one sector at a time can be erased using a sector erase instruction. Instructions are completed quickly, saving time during operation, as well as during production testing and programming.

Among the M25P20's industry-leading performance figures are 84us for a full memory read operation (at 2.7V); 2us (typical) for 256-byte page programming; and 64 Kbytes sector and 256 Kbytes erase operations of 2s and 4s (typical), respectively. Allowing either random or sequential read operations, the serial memory reduces the number of instructions needed compared to a parallel architecture, simplifying development. The four-wire SPI-compatible serial interface clocks at a top rate of 25MHz.

Other features of the M25P20 include a -40(degree) to +85(degree) temperature range, 1uA (typical) deep power-down mode, and an 8-bit electronic signature. Drawing on ST's high-endurance CMOS flash technology, the M25P20 allows at least 100,000 program-erase cycles per sector. The memory also retains data for at least 20 years.

The M25P20 enlarges the M25Pxx family of serial flash ICs that reflects a trend away from parallel architectures toward space-saving serial designs.

By the end of first quarter 2002, 4-Mbit devices and above, are due to be announced. The M25P20 2-Mbit serial flash memory comes in a 150-mil-wide SO8 package and is available now.

Link:
STMicroelectronics