I am beginner in fpga. So i need help for my project. I have used 16 adc0804 in my project. The input for adc is from my 16 receiver curcuit. And now I want to interface the adc with FPGA. But i am very confusing. From my understanding, the output from adc0804 is digital. So, i just need to connect the output at DBn to gpio of de2 board. Is it correct guys? kindly help me please:---(
Thanks for your reply. Yes. it is my adc that i have used. So, do you mean that i just connect the DBn, intr, cs,wr, rd to GPIO of FPGA? Then i need to control cs,wr,rd signal? Could you explain little bit more detail. I still confuse.
The solution is not completely obvious, there are different options:
- Implementing a common data bus for all ADCs, sequentially accessing the data
Advantage: less FPGA pins
Disadvantage: more complex logic
- Individual data lines for each ADC
Advantage: Simple logic, fast access without sequences. Some ADC pins can be connected to fixed level, at least nCS.
Disadvantage: many FPGA pins needed
First you need to think on how you can reduce the number of ADCs from 16 to some convenient number say 4 or 5. Then it will be easier for you to think of interfacing ADCs to the fpga.
if you use a 'n' channel diff mux, things will be much simpler. Refer to the attached figure taken from the DS. This should help you. Later try using a configuration similar to Fig 61 - Interfacing Multiple A/Ds in an MC6800 System.
Thanks for your reply. I am very very beginner in vhdl. I have write some code for the adc and i know its wrong. But could you give me some ideas how to build the vhdl