SN65DSI83-Q1: Use this bridge to convert MIPI DSI from STM32H7 to the LVDS display 1024x600

Petr Bilek

Prodigy 40 points

Part Number: SN65DSI83-Q1
Other Parts Discussed in Thread: SN65DSI83, SN65DSI85, SN65DSI85EVM, DSI-TUNER

Hello,

I would like to ask you, if is it possible to use this MIPI DSI bridge (SN65DSI83-Q1) in my application.

I am currently using STM32H747 microprocesor as the discovery kit

https://www.st.com/en/evaluation-tools/stm32h747i-disco.html

and I need to connect it with this 7 inch display, 1024 x 600, LVDS

https://www.unisystem-displays.com/en/products/lcd-tft/standard/wf70a8syahlnn0.html

The STM32H7 has MIPI DSI interface and the display has LVDS interface. I am going to use the SN65DSI83-Q1 as a MIPI/LVDS bridge to conncet the microprocesor and display together.

According to the datasheet I am convinced that the SN65DSI83-Q1 is the device, what I need.

Can you confirm my opinion please?

Is it realy possible to use the SN65DSI83-Q1 with STM32H7 and the LVDS display please?

Thank you in advance for your message.

Regards,

Petr

over 6 years ago

0 Ikechukwu Anyiam over 6 years ago

TI__Mastermind 35130 points

Hi Petr,

Do you have the specifications for the DSI interface on that MPU? I don't see any in the link provided.

Regards,

I.K.

0 Petr Bilek over 6 years ago in reply to Ikechukwu Anyiam

Prodigy 40 points

Hello,

Thank you for your message.

The datasheet is included below:

https://www.st.com/resource/en/datasheet/stm32h747xi.pdf

The specification of MIPI DSI is in 6.3.11 PLL characteristics chapter on the page 137/242.

The Best Regards,

Petr

0 Ikechukwu Anyiam over 6 years ago in reply to Petr Bilek

TI__Mastermind 35130 points

Hi Petr,

Thanks, the datasheet says it is compliant to the MIPI DSI spec so there shouldn't be an issue with using it with the DSI83.

The LVDS display looks okay but I don't understand how they spec'd the blanking parameters in the timing table in the datasheet. Most LVDS display timing tables look like the table on page 17 of this datasheet: https://e2e.ti.com/cfs-file/__key/communityserver-discussions-components-files/138/SPF_2D00_PH128800T004_2D00_ZHC_5F00_002_5F00_black-border.pdf

Regards,

I.K.

0 Petr Bilek over 6 years ago in reply to Ikechukwu Anyiam

Prodigy 40 points

Hello,

Thank you. I plan to order the SN65DSI85 board, it seems to be more versatile than the older SN65DSI83 and the pinout should be the same.

Now I would like to ask you, how to connect H747 Discovery board to the SN65DSI85 board? The Discovery has 60 pin DSI output and the SN65DSI85 board has 40 pin DSI input. Is there any adapter fot it or special cable? In the worst case I can order SAMTEC conncetors and make the connection myself....

On the side of LVDS display, the pinout should be the same, so it should work if the LVDS display is connected directly to the SN65DSI85 board. To be honnest I have no idea about the timing....

Thank you very much for your help.

The Best Regards,

Petr

0 Ikechukwu Anyiam over 6 years ago in reply to Petr Bilek

TI__Mastermind 35130 points

The SN65DSI85EVM was designed to mate with the connectors on a PandaBoard, so you will need to use an adapter if your board doesn't have the same connector.

For timing you can reference this training video as an example: https://training.ti.com/configuring-sn65dsi8x-single-channel-dsi-single-link-lvds-operation

I recommend using the DSI-Tuner to help configure the device.

Regards,

I.K.

0 Petr Bilek over 6 years ago in reply to Ikechukwu Anyiam

Prodigy 40 points

Hello,

Thank you. I realized that the STM32H7 has two link MIPI DSI output and the display has 4 link LVDS input. Does it play any role? The SN65DSI83/5-Q1 has 4 link MIPI DSI input. Is it possible to set up the chip SN65DSI83/5-Q1 to two link MIPI DSI input and 4 link LVDS output?

We have it for automotive dashboard.

Thank you.

Regards,

Petr

0 Ikechukwu Anyiam over 6 years ago in reply to Petr Bilek

TI__Mastermind 35130 points

Hi Petr,

I saw that too and yes it will play a role. It means you will need to use a faster DSI CLK than normal to maintain the line time. The DSI CLK frequency equation is in the video I shared, but it is also equation 2 in this app note: https://www.ti.com/lit/an/slla356/slla356.pdf

For the 65 MHz LVDS CLK your display requires the DSI CLK has to be 390MHz if there are only 2 DSI Data lanes.

Regards,

I.K.

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SN65DSI83-Q1: Use this bridge to convert MIPI DSI from STM32H7 to the LVDS display 1024x600