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Visitor
Visitor
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Registered: ‎10-25-2018

MIPI DPHY (Rx) Simulation Issue - Reset / INIT_DONE Related

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Hi, 

I am trying to simulate the Xilinx MIPI Rx DPHY integrated with a custom MIPI CSI2 Rx controller. There are no issues w.r.t integration and we have been able to also get the cadence based simulation test bench functional too. 

In the sim environment, all test cases have passed except one. On debugging the failed test case, we figured out that the "init_done" of the MIPI Rx DPHY wasn't getting asserted after the DPHY reset. The reason for this seems to be an active clock being driven on the mipi rx clock lane : "clk_rxn/p". However, if we force this differential clock lane to high (both p and n to high), then the "init_done" is asserted within 100 us.

Ideally, the Rx DPHY should not expect the clock lane to be inactive when it's reset, as it has no control on the clock driver (Tx DPHY). Can anyone tell me if this a Xilinx MIPI Rx DPHY model issue ? Or is there something subtle that we need to be aware of, so this won't affect our final system functionality when implemented on the FPGA ?

I am using Vivado 2018.3 and Virtex Ultrascale+ FPGA (xcvu9p) part configured for 1500 Mbps as lane rate.

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Xilinx Employee
Xilinx Employee
96 Views
Registered: ‎03-30-2016

Re: MIPI DPHY (Rx) Simulation Issue - Reset / INIT_DONE Related

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Hello @spr_ad 

 

MIPI D-PHY RX needs to observe LP-11 on its inputs (for both clock and data lanes), to finish its initialization process.

Without LP-11 , init_done will not be asserted. It is also applicable on the actual HW.

INIT_VAL.png

RESET.png

Thanks
Leo

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Xilinx Employee
Xilinx Employee
97 Views
Registered: ‎03-30-2016

Re: MIPI DPHY (Rx) Simulation Issue - Reset / INIT_DONE Related

Jump to solution

Hello @spr_ad 

 

MIPI D-PHY RX needs to observe LP-11 on its inputs (for both clock and data lanes), to finish its initialization process.

Without LP-11 , init_done will not be asserted. It is also applicable on the actual HW.

INIT_VAL.png

RESET.png

Thanks
Leo

View solution in original post