eda is electronic design automation, asic application-specific integrated circuit, pld programmable logic device, fpga field programmable gate array.eda technology is to use computer as a tool, designers on the eda software platform, with hardware description language hdl to complete the design file. Then the computer automatically completes the logic compilation, simplification, segmentation, synthesis, optimization, layout, wiring and simulation, until the adaptation compilation, logic mapping and programming download for the specific target chip. And the application in programmable logic devices (such as cpld, fpga) has been widely popularized. In the integrated circuit community, an asic is considered to be an integrated circuit designed for a special purpose. It refers to the integrated circuit designed and manufactured according to the requirements of specific users and the needs of specific electronic systems. Modern ASics often contain the entire 32-bit processor, memory units such as rom, ram, eeprom, flash, and other modules. Such ASics are often referred to as soc(System on Chip). fpga is a close relative of asic, which generally uses schematic diagram and vhdl to model the digital system, uses eda software to simulate and synthesize, generates network tables based on some standard libraries, and can be configured to the chip. The difference between it and asic is that the user does not need to intervene in the layout and process of the chip, and can change its logic function at any time, and the use of flexible. pld is produced as a general purpose integrated circuit, and its logic function is customized according to the user's device programming. The integration degree of general pld is high enough to meet the needs of designing general digital systems. At present, the main pld products in peaceful and use are:
1, field programmable logic array fpla;
2, programmable array logic pal;
3, universal array logic gal;
4, erasable programmable logic device epld;
5, field programmable gate array fpga. The integration of epld and fpga is relatively high. These two devices are sometimes referred to as high-density PLDS. Then it can be said that fpga is just another way of expression of eda,asic,pld. It is further developed on the basis of programmable devices such as pal, gal and cpld. It appears as a semi-custom circuit in the field of application-specific integrated circuit (asic), which not only solves the shortcomings of custom circuit, but also overcomes the shortcomings of the limited number of gate circuits of the original programmable device.