System enhancements and cost reduction are becoming major trends for upgrading existing system designs. To be competitive, companies need to enhance their existing feature sets and lower their total cost, providing more for less.

Traditional systems have always used discrete logic devices for implementing the simple glue and control logic that every design requires. The main argument in favor of discrete logic was that it was cheap and easily available. Yet discrete logic was not the most optimal choice from a board area, power consumption, or programmability standpoint.

The introduction of programmable logic devices provided programmability, flexibility, and higher levels of integration. However, it also came at a cost premium over discrete devices.

Improvements in manufacturing processes and packaging technologies in the last 10 years have significantly lowered the cost of programmable logic devices. Today, CPLD unit costs have been driven down to a level such that they can replace discrete logic devices, yet maintain advantages such as higher performance, design flexibility, re-programmability, and reliability (Figure 1).

Logic Consolidator
To help customers quickly and accurately estimate their costs and area savings by using a single CPLD instead of multiple discrete devices, Xilinx® offers a tool called Logic Consolidator. This is a Microsoft Excel-based tool that estimates the number of discrete logic devices that can be integrated into a single CPLD. It compares Xilinx XC9500XL and CoolRunner™-II 10,000-unit pricing to the 10,000-unit average resale price of 7,400 discrete logic products in the lowest cost plastic package. Also, based on particular quotes, you can specify your own unit pricing for accurate comparison.

Logic Consolidator makes life easy for designers as well as managers. For purchasing managers, the easy-to-use Excel tool enables them to accurately list the number of near-obsolete discrete logic devices that can be replaced by the most optimal Xilinx CPLD – and the cost savings justifying such an upgrade. For designers, it saves precious design time that is usually spent estimating the right PLD to replace a range of discrete logic devices.

In this article, we’ll present a real-life case study where Logic Consolidator helped a customer analyze the real cost benefits provided by Xilinx CPLDs over discrete logic devices, saving thousands of dollars in the process.

Customer Case Study
The Logic Consolidator tool was instrumental in convincing an initially skeptical customer to integrate all of the discrete logic on their board to a single Xilinx CPLD.

Wipro Technologies, one of the biggest hardware design services companies in India (and a Xilinx XPERTS partner), was working on a project aimed at upgrading an existing telecom product, mainly to cut manufacturing costs and include some enhanced features. During the initial stage, CG-CoreEl’s Xilinx sales team introduced Logic Consolidator to the customer and helped them identify the appropriate CPLD for replacing multiple discrete devices on board.

The tool is very intuitive. It saves a lot of time in finding the right CPLD to replace all of the discrete logic. Figure 2 shows a screenshot of the Logic Consolidator tool as used by the customer.

In this case, Wipro was able to identify 73 discrete logic devices that could be replaced by a single Xilinx CPLD. They could choose either a XC9500XL device or a CoolRunner-II device, depending on the supply voltage available. Both options offered an immediate bill-of-materials cost savings – $0.74 with the XC95288XL device and $1.81 with the XC2C256 device, with about 40% more room available in the CPLD to add more logic for any feature enhancement.

When Wipro engineers actually implemented the design, because of optimizations performed by the Xilinx ISE™ software tool, the design fitted in the next smallest Xilinx device, the XC95144XL-10TQ144C, with 144 macrocells With a listed price of $6.45 for the XC95144XL device, it provided further cost savings for the customer. On the PCB front, the potential savings are approximately more than 70% in board real estate, 60% or more in board routing, and a 50% reduction in board design time.

Add to this the benefits of programmability, reduced board complexity, and increased reliability through reduced power consumption and lower EMI, and it was apparent to Wipro that the Xilinx CPLD was the obvious choice.

After using Logic Consolidator for this card, Wipro was so impressed with its efficiency and usefulness that they decided to use it for all of the other cards in their telecom product upgrade project, and are planning to use it in future projects as well.

Conclusion
Logic Consolidator is a powerful tool that allows customers to analyze the costs of different alternatives for themselves. Because it is built using Microsoft Excel, it is easy to learn and use. To get a copy of Logic Consolidator, contact your Xilinx sales representative. And for more information about or to download Logic Consolidator, visit www.xilinx.com/products/cpldsolutions/logic_tool.htm. A new version now includes more logic device choices.

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