Intel® Quartus® Prime Software
Intel® Quartus® Prime Design Software, Design Entry, Synthesis, Simulation, Verification, Timing Analysis, System Design (Platform Designer, formerly Qsys)

PCI Clamp Diode

Altera_Forum
Honored Contributor II
2,016 Views

Hi, 

 

Does anyone know how to disable the PCI clamp diode for individual Inputs on a Flex10KE within Quartus ?. I have the I/O configured for LVTTL but the inputs are being clamped by the clamp diode. 

 

 

Thanks 

 

 

Graham
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Altera_Forum
Honored Contributor II
1,125 Views

The FLEX 10KE manual tells different: 

 

--- Quote Start ---  

The PCI pull-up clamping diode, slew-rate control, and open-drain output options 

are controlled pin-by-pin via Altera software logic options. 

--- Quote End ---  

 

The actual configuration can be reviewed in the fitter resource section anyway, PCI clamp diodes should be controllable via Pin Planner or Assignment Editor as for any FPGA family.
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Altera_Forum
Honored Contributor II
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I haven't tested it for the FLEX family, but usually you set 'PCI IO' assignment with value 'off' to disable the clamping diode.

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