"Turn on" LVDS output?

Michael,

OMAP does not have LVDS driver outputs. You will need to add an external LVDS serializer such as the LVDS83B.

BR,

Steve

Hmm, then what does all this mean in the OMAP35x Technical Reference Manual?:

"15.2.1.2 SDI Serial Interface

The SDI module implements the TI FlatLink3G protocol and converts the conventional parallel display signals (including pixel data) from the display controller to serial form. Texas Instruments provides a global solution with OMAP device associated to a programmable 27-bit serial display interface receiver - SN65LVDS302 receiver for 3-data pair, SN65LVDS304 receiver for 2-data pair, and SN65LVDS306 receiver for 1-data pair."

And the following figure 15-33 that shows an SDI interface (SDI_DATA_1N/1P/2N/2P/3N/3P, SDI_CLKP/N pins interfaced directly with an LCD panel?

SDI is a form of LVDS, but it is not what the LCD you are using likely needs. SDI is based in FlatLink which is subLVDS.

The formatting of this interface is different to LVDS used on the larger displays.

subLVDS has a voltage swing of +-150mV whereas LVDS has +-1.1V. The clock to data ratio is also different.

Basically, SDI is subLVDS which is quite different to LVDS at both the physical and logical levels.

If you can let me know the LCD model number and/or data sheet I will check for you.

Additionally SDI is not supported on the OMAP35xx devices. This should really be removed from the TRM I think.

BR,

Steve

You think??   You mean the hundreds of pages describing the SDI in the "OMAP 35x Application Processor Technical Reference Manual" (SPFUG98L - Revised November 2010, ) are just a big typo?  Shouldn't they have fixed that when they just revised the manual this month?

What else in this 3440 page manual is wrong?  Does the 3530 really not have a DSP?   A camera interface?   We are depending on your documentation to make a lot of design decisions, so it would be good to know when the manual is so egregiously invalid!

I do see in Table 1-3 that the 3530 has an "LCD and TB Output", but no DSI, and SDI is not mentioned in this table. First mention of SDI in is Figure 4-74 Voltage Distrib., then Table 7-4 Pad Config, then not again until Chapter 15.

Is the older OMAP3530/25 data sheet (SPRS507F - Revised October 2009) the more accurate reference?  In it's Display Subsystem summary it only mentiones RGB output (RFBI), and NTSC/PAL and S-Video.  No SPI / LVDS.

Thanks for the input.  I'm just disappointed about incorrect documentation and missing features we thought we had available.

Michael Schwab

Mike,

Much of the documentation is derived from other devices in the product family. It is important that you determine the exact features of a given derivative product number.

I would say though that the hardware is there it is just not supported directly by TI for the mass market. There are community and open source drivers available and you can find additional information by doing a Google search for OMAP3 SDI for example.

Regarding the 34xx vs 35xx... The 34xx devices are not released to the mass market, only the 35xx devices. If you need access to the 34xx features then you should contact your local TI sales rep for more information.

I have passed your comments on to the appropriate folks handling the documentation.

Regarding your immediate issue though, the SDI output is subLVDS and not LVDS which is what I think you need. We do not have integrated LVDS drivers in any of the device families.

BR,

Steve

Thanks, Steve,

Yes, our EE is already wiring up a full LVDS transmitter that is compatible with the device you mention.

I'm not sure what you even mean by 34xx features.  I haven't researched that family at all, since the board presented to me for eval has a 3530.  The tech manual I have mentioned is supposedly only talking about 35xx features.  What features (besides the SDi, which we can't use anyway) might we want that are only offered on the 34xx?

And what is the definition of "mass market"?  The ultimate client (who will be buying the parts) is a huge medical equipment company, so they are not a casual consumer.

Thanks again,

Michael Schwab

Sorry, I mis-read "What else in this 3440 page manual is wrong?" as though you were referencing the 34xx family of devices. These are not available to the mas-market, but I thought you had been investigating them through your local sales rep.

BR,

Steve