[DM816x]How can DM816x support the LCD using VOUT1 port?

Matt,

Yes it is possible to display the same content on different outputs at different target resolutions.

It is possible to use the scaler to scale the larger frame buffer image down to fit your smaller LCD which can then be connected to VOUT0.

VOUT1 must be configured to the same resolution etc... as the HDMI so if you need to use the scaler to output a different resolution for your LCD then you can't use VOUT1.

BR,

Steve

Steve,

Actually, our system is need 3 output interfaces: HDMI is connected to HDTV, RGB888(VOUT0) is  connected to a  small LCD panel, and VOUT0 is used to connect to another monitor with DVI interface, on which the  content shown is different with that on HDTV and LCD.

As you mentioned, VOUT0 must be configured to the same resolution as the HDMI, I think it is mean that I can't use the LCD and HDMI "at the same time".

For our system,  it is not a important requirement that displaying the content on the LCD and HDMI simultaneously, so how about to use them "not" at the same time?  Say when I use the HDMI, I configure higher   resolution, and when I want to use the LCD, I change to the smaller resolution.  Is that possible?

And the key problem is how can I use the VOUT1 to connect the LCD(RGB888). Does TI or other vendors have the solution to convert  VOUT1(maybe YCbCr or BT656) to RGB888.

Understood.

Yes, the resolution can be changed dynamically so you can switch between HDMI and your LCD.

Both digital output ports support RGB so you do not need any external conversion.

BR,

Steve

Really?!

It is the good news if it is true:)

I check the datasheet(tms320dm8168.pdf，page 249  )  before, and it say:

 So I always think. VOUT1 can't support RGB mode.

Does anybody can help to confirm if  VOUT1 supports RGB mode?

Hi,

VOUT1 supports RGB101010 mode with discrete as well as embedded sync.  Currently we have by default enabled the on-chip HDMI pin mux. If you want to connect the LCD to the Vout1 you will have to enabled the pin mux for the RGB pins and the sync pins looking at data sheet. You can control the output colorspace and the sync type using the following sysfs entry for displays

/sys/devices/platform/vpss/displayx/output

display0 --> on-chip HDMI/ Vout1

display1 --> vout0

display2 -->sd venc

display3 --> hdcomp/hddac/

Regards,

Hardik Shah

Hi,

It should be possible to output RGB30 bit with the separate sync by changing PINMUX settings, which is hardcoded, as of now, in the HDVPSS driver to provide preference to the VIP input pins. This is done at the drivers init time so you can overwrite the settings as per your requirement after drivers init.

Thanks,

Brijesh Jadav

I am looking for the same information as the original poster, but I'm confused by this answer - according to the datasheet VOUT1 only has pins VOUT[1]_C[9:2] and VOUT[1]_Y_YC[9:2] (16 bits).  VOUT0 has the 30 pin interface.  If VOUT1 does support a 30 bit mode, how does the data get mapped to the pins?

IMHO The docs are sorely lacking in this section - the interface information should all be in the tech reference manual, not buried in some software driver wiki or random postings on e2e.

Hi

Andrew Dyer said:

according to the datasheet VOUT1 only has pins VOUT[1]_C[9:2] and VOUT[1]_Y_YC[9:2] (16 bits).  VOUT0 has the 30 pin interface

You are correct here.

VOUT1 doesn't support 30-bit interface. But Venc inside VOU1 is directly connected to HDMI. This is through 30-bit interface. So external encoder can be connected for only 16-bit interface as you figured out.

Regards,

Hardik Shah

OK, now I understand the 30 bit reference.  In the case where 30 bit RGB mode is enabled internally, what data shows up on which VOUT1 pins?

Hi,

In case you set Venc for 30bit RGB you will get only two components. But you can set venc in 20-bit YUV mode also. In this case you will be able to get 8-Y and 8-C bits without truncation.

Regards,

Hardik Shah