adc0804 interfacing with fpga

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Maxima8

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Hi guys.

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:---(
 

Hi shaiko.

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.
 

DBn, intr, cs,wr, rd to GPIO of FPGA
Click to expand...
Yes,
Together with the data pins. That's quite a bit of wires...

Afterwards, you'll have to implement the control logic according to the waveforms in page 7.
 

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.
 

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shaiko said:
Yes,
Together with the data pins. That's quite a bit of wires...

Afterwards, you'll have to implement the control logic according to the waveforms in page 7.
Click to expand...


Hi shaiko.

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
 

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1. Your code won't compile due to syntax issues.
2. Even if it would compile - it won't synthesize. You can't use "after" to describe real logic.

I suggest you acquire minimal VHDL skills before you continue
Please watch this video:

**broken link removed**
 

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