How Do You Implement ADC On FPGA Using VHDL Code?
You can’t. You are trying to implement an “analog to digital converter”. Unless your FPGA already has analog sections on the same semiconductor die this isn’t possible. FPGA stands for “Field Programmable Gate Array” – all it is is a bunch of DIGITAL gates that can be configured to do a number of different things. The I/O’s only understand 1 or 0, 0V or 3.3V, etc without any inbetweens. You can use an FPGA to interface to an ADC (as a separate IC) a number of different ways. You can have an FPGA run all the I/O’s of the separate chip to pull in the analog value as a digital value. The other option is to use a voltage-to-frequency converter and then use a counter in your FPGA to generate an accurate analog voltage. If you have a special FPGA with ADC’s built into the chip you will have to check the documentation that comes from the FPGA manufacturer. VHDL is digital only – it does not allow for anything analog. Therefore a special FPGA would have put its own extensions on VHDL.
