hello please I am looking for a VHDL description, for analogue-to-digital decoder, with analog input, and an output of 8 bits. if someone have information . thanks

What do you need this "converter" for? What is a "analog value"? You know that you cannot synthesize such a description on a FPGA?

hello thank you for your help. Therefore the analog value is a voltage between 40 and 200 mV. I'm not really a profissionnel in the field. I want this converter to find two numerical values for comparison, if not. can I compare two voltage without converting them.

hossam wrote: > hello > thank you for your help. Therefore the analog value is a voltage between > 40 and 200 mV. I'm not really a profissionnel in the field. > I want this converter to find two numerical values for comparison, if > not. can I compare two voltage without converting them. Yes you can, all what you need is an OPAMP with sufficient gain. You can't implement an analog circuit directly with VHDL in a FPGA. Some FPGA come with a low speed ADC (just like the one in many microcontroller) which you can access from VHDL. You can also implement a sigma delta ADC in a FPGA using VHDL, but this also requires an external comparator (OPAMP).

hossam wrote: > can I compare two voltage without converting them. With acomparatoryou can easily determine, which one of two voltages is higher...