AWS EC2 FPGA Hardware and Software Development Kit

Re:AWS EC2 FPGA Hardware and Software Development Kit by bedros on Wednesday April 19, 2017 @06:13PM (#14152294)

I have not read the whole FPGA HDK guide yet, but, I doubt amazon will give the designer access to pins on FPGA; they would give access to interfaces or IO blocks which connect to the pins

your design sits inside a wrapper with access to IO blocks.

inside the FPGA logic, you cannot do electrical damage, no matter how hard you try.

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Re:AWS EC2 FPGA Hardware and Software Development Kit by btown on Wednesday April 19, 2017 @06:16PM (#14152314)

Thermal damage may be possible, but they probably have monitoring that will shut down your logic if overheating is detected.

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Re:AWS EC2 FPGA Hardware and Software Development Kit by CamperBob2 on Thursday April 20, 2017 @01:03AM (#14154094)

inside the FPGA logic, you cannot do electrical damage, no matter how hard you try.

I'd be a little worried about people making ring oscillators and driving them from the fastest possible output from a DCM. That used to be a hazard, not sure if it still would be at the UltraScale level of play.

Or creating a configurable DCM or PLL and then setting it up with illegal values at runtime, when the synthesis tool won't notice...

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Re:AWS EC2 FPGA Hardware and Software Development Kit by mikejmoffitt on Wednesday April 19, 2017 @06:39PM (#14152433)

You could have a lot of combinational logic dependent on floating/high-Z inputs, which is not good for CMOS circuitry.

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Re:AWS EC2 FPGA Hardware and Software Development Kit by dahtguy on Wednesday April 19, 2017 @06:48PM (#14152484)

What's so bad about high-Z inputs? Designing around a floating input is the same as designing around an undefined variable. Bad design but you can't "hurt" the hardware.

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Re:AWS EC2 FPGA Hardware and Software Development Kit by femto on Wednesday April 19, 2017 @07:26PM (#14152697)

An undefined variable is an abstract construct. You can model a floating input in as being analogous to an undefined variable and the model will fit reality most of the time, but the underlying reality is still governed by the complexities of physics, with potential for the model to break down.

Damage is probably more of a risk for an external I/O, but it's still a possibility for an internal I/O. Probably more of a certainty with a malicious programmer.

Who's going to be the first person to design an on-die switched capacitor voltage multiplier, using parasitic capacitance between gates as the energy storage, and use it drive an internal high impedance input to a damaging level?

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Re:AWS EC2 FPGA Hardware and Software Development Kit by duskwuff on Wednesday April 19, 2017 @07:20PM (#14152656)

The only tristate buffers in modern FPGAs are on the pins. There's no way to leave inputs floating internally.

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Re:AWS EC2 FPGA Hardware and Software Development Kit by bedros on Friday April 21, 2017 @03:42AM (#14163742)

Z logic or tri-state logic are not real in FPGAs, they are chains of AND OR logic

so basically you cannot burn FPGA by making a short-circuit

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Re:AWS EC2 FPGA Hardware and Software Development Kit by mikejmoffitt on Wednesday April 26, 2017 @04:48PM (#14206851)

A floating pin on a CMOS device is absolutely real.

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