MIPI D-PHY configuration for 4 pcam

[manboy]

Hi all,

I download the "ZedBoard-FMC-Pcam-Adapter-Dual-Camera-2018.2-1" and open it on vivado 2018.

There are four MIPI D-PHY (A,B,C,D). In #A, we have a RxByteClk = 84MHz, which can be derived from total data rate =1344Mbps.

However, when i check the configuration of #B,#C,#D, all of them have RxByteClk = 25MHz. 

Can I know how the difference or how the 25MHz be derived?

 

Thanks.

BR

 

[JColvin]

Hi @manboy,

I asked another engineer more familiar with the Pcam about this.

Thanks,
JColvin

[manboy]

On 8/4/2020 at 6:39 AM, JColvin said:

Hi @manboy,

I asked another engineer more familiar with the Pcam about this.

Thanks,
JColvin

Thanks. Waiting for your new comment

[elodg]

It could be that 25MHz is some propagated value but starting with 100MHz MIPI clock from MIPI_DPHY_Receiver_ooc.xdc (out-of-context synthesis) and 84MHz is calculated from a MIPI clock constrained in the top-level design.

I think this is missing constraints bug in the demo projects. We will look into it.

[thinkthinkthink]

Hi,

Sorry it took so long but we have found a fix for this problem and I'll demonstrate it using screenshots.

First of all make sure you have your Block Design opened in a Tab in Vivado. Then go to File -> Export -> Block Design and save it in the default location preferably or wherever else you want. This operation generates and exports the Tcl script that can be used to recreate this block design.

Now go to the Sources tab, right-click on the wrapper and select Remove File from Project..., also make sure you check the Also delete the project local file/directory from disk and press OK.

When prompted make sure the Automatically pick new top module option is selected and press OK.

You'll now need to delete the current block design so make sure you have exported it to a memorable location such as the default location, which should be the vivado_proj folder.

 

This next step requires you to open the system.tcl file which will be used to recreate the block design and edit it with your text editor of choice.

Go to line 244 and copy it along with lines 245 and 246 and paste them after each set dphy_*_hs_clock line so it looks like in the following screentshot:

 

Make sure you save the file.

What you have to do now is to go to Tools -> Run Tcl Script..., find the system.tcl file which you've modified earlier using a text editor and press OK.

Wait for Vivado to finish running the Tcl script and generating the new block design.

Right click on the new block design and select Create HDL Wrapper..., when prompted make sure the Let Vivado manage wrapper and auto-update option is selected and then press OK.

Right click on the newly created wrapper and choose Set as Top.

And now to demonstrate that it actually worked I'll include a screenshot of the MIPI_D_PHY_RX_C IP and if you look at the properties of pin RxByteClkHS you can see that it now says that it's frequency is indeed 84 MHz just like for the MIPI_D_PHY_RX_A IP.

We have found another thing wrong with the project that can easily be fixed by opening the timing.xdc in Vivado's own text editor like so:

Now go to line 20 of timing.xdc and write dphy_*_hs_clock_clk_p after get_ports.

Ok, this should be all, you can save the timing.xdc file as well as the whole project and generate a new Bitstream.

 

 

 

 

[manboy]

Thanks for think^3's solution.

Now, we can have 4 CAM with the same 84MHz's byte clock. ?

[iyer25]

hello @JColvin

I was just trying to wrtie dsa file for v2019.1.

https://github.com/Digilent/ZedBoard-FMC-Pcam-Adapter-DEMO/releases/tag/v2019.1-1?_ga=2.57965992.327743438.1605606962-207701440.1588249171

is it possible? If yes, how to set platform properties? 

everytime I tried doing, there was errors like ----

INFO: [Vivado 12-4895] Creating DSA: system.dsa ...
ERROR: [BD 41-2088] No default platform clock is selected. Please set property is_default to true for one of the platform clocks
ERROR: [Vivado 12-5878] Failed to generate hpfm file for BD File: C:/Users/Utilisateur/Documents/vivado/release/ZedBoard-FMC-Pcam-Adapter-DEMO/ZedBoard-FMC-Pcam-Adapter-DEMO.srcs/sources_1/bd/system/system.bd
ERROR: [Common 17-53] User Exception: Unable to get hpfm file from project property dsa.hpfm_file or from the BD itself.