SN65DSI85: SN65DSI85

gopal sharma

Prodigy 180 points

Part Number: SN65DSI85
Other Parts Discussed in Thread: DSI-TUNER

Tool/software:

Hi,

LVDS display parameter are-

LCDBIT 24 //RGB888
LCDWIDE 1920
LCDHIGH 720
Frame 60 hz
VBPD 3
VFPD 8
VSPW 2
HBPD 16*2
HFPD 16*2
HSPW 8*2

Required Clock is in between 85 to 102.6 Mhz Typically 88 MHz

Please Help me to figure out Mipi-dsi Required input Clock Rate and Configuration of Bridge sn65DSI85 Registers.

Thanks,

11 months ago

0 Vishesh Pithadiya 11 months ago

TI__Mastermind 38275 points

Hey Gopal,

Please use the DSI tuner tool to calculate these values.

Here is the tool. Keep in mind you need java to run this script.

3730.DSI-Tuner.zip

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

hi,

we used dsi-tuner but DSI clock configuration parameter is not generated.

we have successful generated test pattern but no display with DSI interface.

please kindly share DSI clock configuration from host side.

thanks,

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Hey Gopal,

The suggested DSI clock is 264MHz.

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

Hi,

Please Kindly check DSI-TUNER Parameters According to LCD .

1. LVDS Configuration

2.DSI Configurations

3. Calculated Output

3. CSR Output

//=====================================================================
// Filename : CSR_dsi85_1920720.txt
//
// (C) Copyright 2013 by Texas Instruments Incorporated.
// All rights reserved.
//
//=====================================================================
0x09 0x00
0x0A 0x07
0x0B 0x08
0x0D 0x00
0x10 0x26
0x11 0x00
0x12 0x00
0x13 0x00
0x18 0x6f
0x19 0x00
0x1A 0x03
0x1B 0x00
0x20 0x80
0x21 0x07
0x22 0x00
0x23 0x00
0x24 0x00
0x25 0x00
0x26 0x00
0x27 0x00
0x28 0xd2
0x29 0x07
0x2A 0x00
0x2B 0x00
0x2C 0x08
0x2D 0x00
0x2E 0x00
0x2F 0x00
0x30 0x02
0x31 0x00
0x32 0x00
0x33 0x00
0x34 0x10
0x35 0x00
0x36 0x00
0x37 0x00
0x38 0x00
0x39 0x00
0x3A 0x00
0x3B 0x00
0x3C 0x00
0x3D 0x00
0x3E 0x00

4.LCD Info-

Thanks

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Hey Gopal,

I filled this out based off of the datasheet captures provided:

Fullscreen CSR_Gopal.txt Download

//=====================================================================
// Filename   : CSR_Gopal.txt
//
//   (C) Copyright 2013 by Texas Instruments Incorporated.
//   All rights reserved.
//
//=====================================================================
0x09              0x00
0x0A              0x03
0x0B              0x28
0x0D              0x00
0x10              0x26
0x11              0x00
0x12              0x36
0x13              0x00
0x18              0x6f
0x19              0x00
0x1A              0x03
0x1B              0x00
0x20              0x80
0x21              0x07
0x22              0x00
0x23              0x00
0x24              0x00
0x25              0x00
0x26              0x00
0x27              0x00
0x28              0x20
0x29              0x00
0x2A              0x00
0x2B              0x00
0x2C              0x08
0x2D              0x00
0x2E              0x00
0x2F              0x00
0x30              0x02
0x31              0x00
0x32              0x00
0x33              0x00
0x34              0x10
0x35              0x00
0x36              0x00
0x37              0x00
0x38              0x00
0x39              0x00
0x3A              0x00
0x3B              0x00
0x3C              0x00
0x3D              0x00
0x3E              0x00


The PLL_EN bit and SOFT_RESET bit are not set as they need to be set per the recommended sequence defined in the datasheet

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

Hi,

Now my colors on screen is different as actual. Please Suggest which section have a Problem.

Thanks,

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Use the internal color bar to test if you are able to display the correct colors

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

hi,

By Bridge Test Pattern For LVDS OUT is Working Fine. But Problem With DSI Data Input.

Frequency measured -

LVDS CLK = 44.38Mhz

thanks,

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Hey Gopal,

If we have the color bar working with the proper colors, then there are two locations the issue can stem from.

1) The DSI config is not correct, i.e. the DSI data is not matching the timings we are expecting.

2) The DSI data has poor signal integrity.

Do we see any change to register 0xE5 when there is discoloring?

Please use the following debugging guide to verify the DSI line timings.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/990480/faq-sn65dsi84-how-to-debug-flickering-video-with-sn65dsi83-sn65dsi84-and-sn65dsi85?tisearch=e2e-sitesearch&keymatch=sn65dsi85#

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

Thank You Vishesh

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Let me know if you have any more questions!

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

Hi,

Thanks For Your support Now Display Working .

But After Some Time It Stop Working Screen Become Blank.

DSI Input is Present But There Is No LVDS Output Signal.

0 Vishesh Pithadiya 11 months ago in reply to gopal sharma

TI__Mastermind 38275 points

Does the register 0xE5 change when the screen becomes blank?

This may be due to a PLL unlock. Try changing the CHA/CHB_DSI_CLK_RANGE up and down one level to see if the PLL is struggling to catch an edge case. Try the same with the LVDS_CLK_RANGE as well.

0 gopal sharma 11 months ago in reply to Vishesh Pithadiya

Prodigy 180 points

let me check

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SN65DSI85: SN65DSI85