what is the difference between ASIC and FPGA

what is the difference between ASIC and FPGA?.

hi
ASIC and FPGA are different in many ways
1.ASIC is faster than FPGA(40 MHz) means we can operate ASIC on much higher Frequency.
2.ASIC takes less area(for certain application) than FPGA
3.FPGA has only routing interconnects coustmize where as in ASIC every layer is coustmized.
4.FPGA are less costlt for small volume but if you want to fabricate a chip in large volume then ASIC can be cost effective.

I also think ASIC uses silicon more efficiently ...

FPGA 40 MHz? Modern FPGAs are more like 500 MHz, if you design carefully.

The big advantage of FPGA is you can reconfigure the entire device in milliseconds.

The big difference is that an FPGA can be reprogrammed many times while for an ASIC once configured there is no way back

ASIC - Application specific Intergrated circuits.

but when u consider FPGA - Field programmable devices.. these are ones in which there are readymade logic cells and as accodin to the user programmed logic these logic cells are fused. but when u consider a ASIC.. there are difference types such as semi customed and fully customed.

Semi customed ASICs are those which consists of standard cells..but when u consider full customed ASICs.. each and every block is programmed and fused only by the designer..

further there are structured ASICs such as channeled and channeless ASICs..

FPGA's are field programmable devices which can be programmed and re programmed as required by the user.
When a user programms a FPGA, there boolean is fused within the FPGA. Cost per FPGA is expensive as patent has to given to the FPGA chip manufacturer.
The user has to choose a particulr FPGA chip in accordance to the complexity of his design.

When you consider a ASIC, the programmer writes a HDL and then simulates it to get the net list.. and then the simulated and synthesised program is given to the design engineer after which dependin on the complexity of the design he choose a semi customed or a full customed ASIC and designs to obtain the end product. Cost of production of one ASIC is expensive.. but when the number of ASICs manufactured increases the cost per unit decreases.

The design flow of an ASIC is

Design entry (HDL Design) --> synthesis (netlist) --> System partationin (dividin the ASIC into several sub systems) --> Floor plannin --> Placement --> Routing

these are the steps whicc are involved in the manufacture of an ASIC.

The ASIC design flow differs from that of a FPGA.

System partitonin,floor plannin, placement and routin procedures are replaced by other steps pertanin to FPGA manufacture.

hope u can get the point

with regards,