Author Topic: configuring FLEX 10K from MCU  (Read 1052 times)

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Offline GTT95Topic starter

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configuring FLEX 10K from MCU
« on: November 18, 2022, 05:13:57 pm »

I aim to use PS (Passive Serial) scheme to configure a FLEX 10K FPGA from microcontroller. Pins DCLK, DATA0 will thus be driven from MCU IOs. After configuration, same IOs will be assigned other functions, which means DCLK and DATA0 might continue pulsing after the FPGA was configured.

My question: is there any issue which could lead the FPGA into troubles or is it safe (provided pin nCONFIG is maintained high to avoid reinitiating a configuration)?


Offline TomS_

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Re: configuring FLEX 10K from MCU
« Reply #1 on: December 25, 2022, 08:00:23 am »
Based on what I understand from the datasheets, once an FPGA signals that it has completed its configuration, it then cascades control to another FPGA (if it were to exist) via the nCEO pin.

In such a situation, the data and clock signals (which are paralleled between all devices to be configured) would continue to pulse, but any FPGAs that have asserted their nCEO pins should no longer be observing them.

So as long as you don't take nCONFIG low to initiate configuration again, it should be fine to do what ever you want with the data and clock pins after configuration is complete.

Someone else could hopefully double check that this is correct.
« Last Edit: December 25, 2022, 08:19:56 am by TomS_ »

Offline GTT95Topic starter

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Re: configuring FLEX 10K from MCU
« Reply #2 on: January 05, 2023, 01:46:51 pm »
Many thanks for your reply.

The fact that other devices can be initialized without disturbing already configured devices most likely proves it should work.

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