Xilinx and ST Microelectronics have produced a “no compromise” PROM with extensive features at a reasonable cost.

When Xilinx set out to design a high-performance and dense PROM that could configure a wide variety of FPGAs at a low cost, they needed to think “out of the box” to meet the monetary, device complexity, and schedule requirements. They also had several important requirements for a partner: world-class Flash Memory technology, system-level and silicon design expertise, and worldwide high-volume production.

After evaluating potential partners, Xilinx chose to collaborate with ST Microelectronics™ to design a new series of feature-rich, high-performance Platform Flash configuration PROMs (Table 1).

Table 1 – Platform Flash PROM family

	XCF01S	XCF02S	XCF04S	XCF08P	XCF16P	XCF32P
Density	1 Mb	2 Mb	4 Mb	8 Mb	16 Mb	32 Mb
JTAG Prog	•	•	•	•	•	•
Serial Config	•	•	•	•	•	•
SelectMap Config				•	•	•
Compression				•	•	•
VCC (V)	3.3	3.3	3.3	1.8	1.8	1.8
VCCO (V)	1.8 - 3.3	1.8 - 3.3	1.8 - 3.3	1.5 - 3.3	1.5 - 3.3	1.5 - 3.3
Clock (MHz)	33	33	33	40	40	40
Package	VO20	VO20	VO20	FS48, VO48	FS48, VO48	FS48, VO48

The Benefits of Partnership
The advantages of designing a complex device with a knowledgeable partner include:

• Reducing schedule timeframes and risk. Platform Flash PROMs use ST Microelectronics’ state-of-the-art 0.15 micron flash technology. They were developed by a seasoned team of system-on-chip system and IC designers.
• Taking advantage of the core competencies and experience of each partner. Xilinx brought more than 20 years of FPGA configuration management expertise to the challenge of designing the Platform Flash configuration PROM. The new device includes multiple modes of configuration (serial, JTAG, and parallel) as well as the ability to easily manage multiple bitstreams and unique features like bitstream compression.
• Designing and producing the right product for the market. With its extensive worldwide FAE force and design centers, Xilinx worked closely with FPGA users to define a PROM that meets the needs of sophisticated system designers.
  Platform Flash PROMs are cost-competitive products that have both the required baseline features as well as new capabilities to make FPGA systems more attractive and flexible.
• Taking advantage of sophisticated flexible worldwide manufacturing expertise. ST Microelectronics has the manufacturing capacity to produce PROMs in high volumes, along with extensive experience in very small form factor packages.

During the product definition process for Platform Flash PROMs, several multiple chip packaging and stacked die approaches were carefully examined. None appeared to be competitive because the goal was to produce a configuration PROM with the highest reliability, lowest cost, and minimum board space. The result is among the world’s most flexible, cost-effective configuration PROMs.

Compression
Higher density Platform Flash PROMs (Figure 1) employ an advanced bitstream compression technology from Xilinx. Compression allows you to store more information in the same memory space, thus reducing cost and board space. Bitstream file(s) are compressed using Xilinx’s ISE design software. The compressed file(s) are then programmed into the Platform Flash PROM, just like any other bitstream file.

The Platform Flash PROM has a built-in decompressor that automatically senses when a compressed file is stored, and decompresses compressed bitstream information on the fly.

Typically, you can get 50% more bits using this advanced compression technology, fitting, for example, a 48 Mb FPGA design (such as a Virtex-II™ 2VP100 design) into a 32 Mb Platform Flash PROM.

Upgrade Management
You can accomplish in-system programming and upgrades via the JTAG port using the industry-standard four-wire Test Access Port interface (IEEE 1149.1). Platform Flash PROMs are IEEE 1532-compliant, adding to the flexibility and total system integration that allows them to be used with other Xilinx IEEE 1532-compliant devices such as CoolRunner™-II CPLDs and Virtex-II Pro™ FPGAs. The Platform Flash PROM architecture integrates unique controls that give it the ability to store multiple bitstreams (Figure 2). A microprocessor or other configuration engine can then activate a bitstream at any time, allowing system administrators to access previous versions of system configuration in the event that a problem with a newly transmitted configuration arises.

Safe updates can be achieved with the ability to store multiple bitstreams. Updated bitstreams can be programmed into the free memory blocks of the Platform Flash PROM without losing the original bitstream.

Conclusion
Developed jointly with ST Microelectronics, the Platform Flash family of configuration PROMs offers users the ultimate in low-cost, feature-rich system options, including compression and bitstream upgrade management.

For more information about the new Platform Flash PROMs, visit www.xilinx.com/xlnx/xil_prodcat_product.jsp?title=PFP.

Printable PDF version of this article with graphics.  (3/15/04) 200 KB