More information about the XC2S400E-6FT256C: The Spartan-IIE Field-Programmable Gate Array family gives users high performance, abundant logic resources, and a rich feature set, all at an exceptionally low price. The seven-member family offers densities ranging from 50,000 to 600,000 system gates. The Spartan-IIE family is a superior alternative to mask-programmed ASICs. The FPGA avoids the initial cost, lengthy development cycles, and inherent risk of conventional ASICs. Also, FPGA programmability permits design upgrades in the field with no hardware replacement necessary (impossible with ASICs). The Spartan-IIE family of FPGAs have a regular, flexible, programmable architecture of Configurable Logic Blocks (CLBs), surrounded by a perimeter of programmable Input/Output Blocks (IOBs). There are four Delay-Locked Loops (DLLs), one at each corner of the die. These functional elements are interconnected by a powerful hierarchy of versatile routing channels. Spartan-IIE FPGAs are customized by loading configuration data into internal static memory cells. Unlimited reprogramming cycles are possible with this approach. Stored values in these cells determine logic functions and interconnections implemented in the FPGA. Configuration data can be read from an external serial PROM (master serial mode), or written into the FPGA in slave serial, slave parallel, or Boundary Scan modes. Xilinx offers multiple types of low-cost configuration solutions including the Platform Flash in-system programmable configuration PROMs. Spartan-IIE FPGAs are typically used in high-volume applications where the versatility of a fast programmable solution adds benefits. Spartan-IIE FPGAs are ideal for shortening product development cycles while offering a cost-effective solution for high volume production. Spartan-IIE FPGAs achieve high-performance, low-cost operation through advanced architecture and semiconductor technology. Spartan-IIE devices provide system clock rates beyond 200 MHz. In addition to the conventional benefits of high-volume programmable logic solutions, Spartan-IIE FPGAs also offer on-chip synchronous single-port and dual-port RAM (block and distributed form), DLL clock drivers, programmable set and reset on all flip-flops, fast carry logic, and many other features.