Reusing Computer Chips

[lupusautomatica]

Hello, all!

I have just a quick question. It's my understanding that computer chips (specifically integrated circuits that are programmed to have a specific set of instructions) are not reusable (that is, can't be reprogrammed to perform different instructions or operations).

For example: It is not possible to reuse the chip found inside a smart card reader.

Am I correct in this belief?

If so, the real important question (whose answer I have been unable to find after diligent searching) is this: Why? What prevents a chip from being reprogrammed?

Disclaimer: this may be a silly question with a simple answer, but as a novice programmer and computer hardware enthusiast, I'm very interested to know.

Thanks in advance!

 

[unksol]

most ICs are exactly that, a hardwired circuit that consists of electronic components to perform a specific function packaged into a chip. They are not programmed. They do not have or run instructions. They are just an electronic circuit.

 

[spooky2th]

I think it depends on the chips. Some are re-programmable and some are not. Like some disks are able to be erased and wrote to again and others are only able to be written to once. Some chips are physically made to perform a certain way with their designed combinations of transistors, resisters and other components.

 

[kanewolf]

The circuit is hard wired into the chip. Some chips CAN be programmed. FPGA (Field programmable gate arrays) are an example. But they are more expensive than a purpose built (that they can make 10 million just alike) device. If you want to convert PCI-e to USB, for instance -- that is a fixed function. The steps necessary don't change. You hard wire something like that. If you want to search for ET, like SETI -- there is a high probability that your search algorithm could change. For maximum processing speed you could do something like that in FPGA. BitCoin mining is something that is also done in FPGA. The vendors that sell these mining boxes do release software updates for them to improve performance, etc.