There are three main types of configurable elements in FPGA: Configurable Logic Module (CLB), I/O Module (IOB) and Interconnect. Among them, CLB provides functional logic elements, IOB provides the interface between package pins and internal signal lines, programmable interconnect resources provide routing paths, and connects the inputs and outputs of CLB and IOB to a suitable network. The voltage applied to the CLB (or core) is called VCCINT. VCCO is the power supply voltage of IOB. Some FPGAs have other voltage inputs, called VCCAUX. The typical values of VCCINT (for CLB) are 1.0V, 1.2V, 1.5V, 1.8V, 2.5V and 3V, and the current can reach 10A or higher. The greater the number of CLBs, the lower the voltage and the higher the current. At startup, VCCINT must rise monotonously, not fall. The most commonly used VCCO voltage (for IOB) is 1.2V, 1.5V, 1.8V, 2.5V, 3.3V or 5V in traditional systems. The current range is 1A to 20A. The auxiliary voltage (VCCAUX) is typically 3.3V or 2.5V. It powers time-critical resources in FPGAs and is therefore susceptible to power supply noise. VCCAUX can share a power layer with VCCO, but only if VCCO does not generate excessive noise.
FPGA Virtex-II Family 1M Gates 11520 Cells 750MHz 0.15um Technology 1.5V 896-Pin FCBGA
Xilinx TQFP
FPGA Spartan-3A Family 700K Gates 13248 Cells 770MHz 90nm Technology 1.2V 484-Pin FBGA
FPGA Spartan-3AN Family 700K Gates 13248 Cells 667MHz 90nm Technology 1.2V Automotive Medical 484-Pin FBGA
Spartan and Spartan-XL Families Field Programmable Gate Arrays
Support
