FPGA Advantages And Disadvantages

FPGA field-programmable gate array is an integrated circuit specified using a hardware description language. It is similar to that of application-specific integrated circuit. Generally FPGAs are used to implement logical function that an ASIC could perform. FPGA contains "logic blocks" that allow the blocks to be wired together and hierarchy of reconfigurable interconnections. . These logic blocks also include memory elements, which may be simple flip-flops or more complete blocks of memory. Logic blocks can be configured to compute complex structures or it can be used to implement simple functions like AND and XOR. Advantages of FPGA includes ability to re-program in the field to fix bugs, lower non recurring engineering costs and shorter

FPGAs are composed of small blocks of programmable logic. Each block contains few registers, configurable logic elements and programmable interconnects and may contain multipliers, multiplexers and counters also. An illustration of a typical FPGA architecture appears in figure below.
FPGA are characterized by following:
1. Number of fundamental logic blocks they contain.
2. Processing speed.
3. Power consumption.
Basic Characteristics of FPGA
1. Logic elements: FPGAs consists of small logic cells. Any digital logic circuit is decomposed into small logic cells which are mapped onto the FPGA logic cells by technology mapping.
2. Lookup tables: each logic cell consists of lookup tables which are like ROM and are capable of implementing any combinational functions of their inputs.
3. Memory: most FPGAs have on-chip memory such as SRAM which is accessible by logic cells and globally.
4. Routing resources: routing is a compromise between programming flexibility and area efficiency. Programmable switches are used for connections in and out Of FPGAs.
5. Configurable I/O: FPGA pins can be configured as TTL CMOS.PCI and other technologies. They include PLLs and clock management schemes

A list of typical applications includes random logic, integrating multiple SPLDs, device controllers, communication encoding and filtering, small to medium seized systems with SRAM blocks, and many more. Other interesting applications of FPGAs are prototyping of designs later to be implemented in gate arrays, and also emulation of entire large hardware systems. Another promising area for FPGA application, which is only beginning to be developed, is the usage of FPGAs as custom computing machines. This involves using the programmable parts to “execute” software, rather than compiling the software for execution on a regular