I cannot understand the setting value of VTC XVtc_Timing

[sankaku525]

I am trying to capture the LCD panel of Sharp LQ110Y3DG02.
Unfortunately, there is no data sheet for this LCD panel.
After trial and error, I can roughly capture.
However, there was a problem of shifting by 10 lines.

I am trying to manually change the timing VBP obtained by VTC, but it does not work.
XVtc_Timing is confusing because it has two identical values.
Is there any documentation explaining these things?

Does what I am trying to do solve the problem?

sdk use 2018.2

xvtc.h

	/* Horizontal Timing */
	u16 HActiveVideo;	/**< Horizontal Active Video Size */
	u16 HFrontPorch;	/**< Horizontal Front Porch Size */
	u16 HSyncWidth;		/**< Horizontal Sync Width */
	u16 HBackPorch;		/**< Horizontal Back Porch Size */
	u16 HSyncPolarity;	/**< Horizontal Sync Polarity */

	/* Vertical Timing */
	u16 VActiveVideo;	/**< Vertical Active Video Size */
	u16 V0FrontPorch;	/**< Vertical Front Porch Size */
	u16 V0SyncWidth;	/**< Vertical Sync Width */
	u16 V0BackPorch;	/**< Horizontal Back Porch Size */

	u16 V1FrontPorch;	/**< Vertical Front Porch Size */
	u16 V1SyncWidth;	/**< Vertical Sync Width */
	u16 V1BackPorch;	/**< Vertical Back Porch Size */

	u16 VSyncPolarity;	/**< Vertical Sync Polarity */

HBackPorch and V0BackPorch the same?

V0FrontPorch and V1FrontPorch the same?

My XVtc_Timing settings

	xil_printf("_setstart_");              //VTCgetValue
	videoPtr->timing.HActiveVideo =	0x0320;//0x0320;		800
	videoPtr->timing.HFrontPorch =	0x006c;//0x006c;		108
	videoPtr->timing.HSyncWidth =	0x0080;//0x0080;		128
	videoPtr->timing.HBackPorch =	0x0016;//0x0016;		22
	videoPtr->timing.HSyncPolarity =0x0001;//0x0001;		1
	videoPtr->timing.VActiveVideo =	0x01e0;//0x01e0;		480
	videoPtr->timing.V0FrontPorch =	0x0007;//0x0007;		7
	videoPtr->timing.V0SyncWidth =	0x0004;//0x0004;		4
	videoPtr->timing.V0BackPorch =	0x0022;//0x0022;		34
	videoPtr->timing.V1FrontPorch =	0xfe21;//0xfe21;		65057
	videoPtr->timing.V1SyncWidth =	0x0001;//0x0001;		1
	videoPtr->timing.V1BackPorch =	0x0000;//0x0000;		0
	videoPtr->timing.VSyncPolarity =0x0001;//0x0001;		1

VBP (V1BackPorch) has been set to 0x0A.
But nothing changes Image.

capture Image

Block Design

Thank you for reading this far.

[watari]

Hi @sankaku525 

What freuqency do you apply as pixel clock to LCD panel ?

Best regards,

[sankaku525]

Hi @watari 

Thank you for your comment.

sorry.
My explanation was missing.
Added diagrams of current system and target system.

The pixel clock in question is obtained from an external video source.
The same applies to Vsync and Hsync.

If you have any concerns about the IP settings, please ask.

Thank you.

[watari]

Hi @sankaku525 

I'm very confused.

What kind of source device do you use ?

Also, how do you apply resolution on it ?

If you don't know proper video timing about "800x480", I suggest you to calculate video timing with VESA CVT rule.

Best regards, 

[sankaku525 · Accepted solution]

Hi @watari 

I was wrong.
Video In to AXI4-Stream thought he was creating an AXI Steram using the VTC Timing parameters.
But that was a mistake.
The cause that confused you was my misunderstanding.
sorry.

This closes the question because the VTC in question did not have any relation to the video disturbance.
I find out more about AXI Steram.
Thank you for giving me a chance to notice a mistake.

Best regards,