Hello Together,
I am debugging my FPGA board.
For debug process. Can I power the peripheral circuit without powering ON the FPGA?
If no, could you please explain why?
The FPGA that I am using is Arria10.

Thanks in advance,
Tensil Sebastian

 

You can do this, but:

1. How will you handle floating inputs in the peripheral circuitry?
2. How will the peripheral circuitry handle an unpowered load of the FPGA?

Once you've answered that for all of the FPGA pins, you're good to go.

Personally, I think this will create more problems than it will solve. If you have time and money to burn, go ahead and run the experiment.

 

Hello Please find my comments below.

You can do this, but:

1. How will you handle floating inputs in the peripheral circuitry?
2. Tenzil: The inputs to the FPGA still driving High or Low, Because the peripherals circuits are powered ON
3. How will the peripheral circuitry handle an unpowered load of the FPGA?

Once you've answered that for all of the FPGA pins, you're good to go.
Tenzil: The peripheral circuits are powered ON and the output is connected to FPGA.

 

Hello Please find my comments below.

You can do this, but:

1. How will you handle floating inputs in the peripheral circuitry?
2. Tenzil: The inputs to the FPGA still driving High or Low, Because the peripherals circuits are powered ON
3. How will the peripheral circuitry handle an unpowered load of the FPGA?

Once you've answered that for all of the FPGA pins, you're good to go.
Tenzil: The peripheral circuits are powered ON and the output is connected to FPGA.

You are not analyzing the situation correctly. Stumble forward if you must.

 

Could you please let me know, what will happen to FPGA if we do so and why

 

Could you please let me know, what will happen to FPGA if we do so and why

An unpowered input on the FPGA with protection diodes may prevent an output from the peripheral circuitry doing much of anything. In the worst case a high current from the peripheral may damage the FPGA input. CMOS inputs in the peripheral area connected to inactive outputs on the FPGA may float and consume excessive power. Without seeing a complete schematic, it is hard to speculate what might happen. Do you really want to open this can of worms?

 

Thank you for the valuable input.

 

Thank you for the valuable input.

Can I add,
something we see a lot, is newcomers to FPGAs
going streight from code to putting into a FPGA

This is a bad habit to get into
by the time one comes to generating the code for the FPGA
you should be certain it will work as you expect,

The answer is the simulator
in FPGAs the simulator is accurate
Over your FPGA life you will spend about 25 % of your time codding
50 % of your time simulating,
25 % of your time synthesising.

I hear the argument "but its a simple FPGA" , "what can go wrong"
Answer, if its simple, the test bench is also simple,
and if it synthesis goes wrong , you could pop the FPGA / external circuit

 

It is not too difficult to remember that microprocessors and FPGAs have always required a multi-disciplinary approach. Programmers have always had difficulty making the hardware work, but circuit designers have been reasonably successful in learning to code. Must be a reason for this.

 

It is not too difficult to remember that microprocessors and FPGAs have always required a multi-disciplinary approach. Programmers have always had difficulty making the hardware work, but circuit designers have been reasonably successful in learning to code. Must be a reason for this.

you might say that, I cant possible comment ,

 

It is not too difficult to remember that microprocessors and FPGAs have always required a multi-disciplinary approach. Programmers have always had difficulty making the hardware work, but circuit designers have been reasonably successful in learning to code. Must be a reason for this.

Interesting viewpoint.

I’ve found that programmers find circuit design straightforward, while circuit designers struggle to learn how to code.

Basically, the circuit designers I’ve observed have trouble understanding why code is necessary at all and hence get stuck.

While programmers are used to designing based on syntax rules and easily extend their understanding to electronic rules of behavior.

Wonder why is that?