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[JeffC]

The website says the FT813 can drive 800x600 displays. Once I go through the datasheet I see little or no mention of the 800 pixel width limitation anymore. 854x480 (FWVGA) has fewer total pixels than 800x600. So could the FT813 drive a FWVGA display ? Or would the extra 54 pixels simply be black ? Thanks a lot!

[BRT Community]

Hello,

The EVE series of ICs do not include a frame buffer, they dynamically clock out each computed pixel on the screen. A displays size and what the Pixel Clock is running at will determine the achievable performance. It is possible to run EVE at higher resolutions, but this will result in a slower refresh rate for the screen.

If we take a working example from the following WQVGA settings:
 

Code: [Select]

// WQVGA display parameters
   lcdWidth   = 800;                                                            // Active width of LCD display
   lcdHeight  = 480;                                                            // Active height of LCD display
   lcdHcycle  = 928;                                                            // Total number of clocks per line
   lcdHoffset = 88;                                                             // Start of active line
   lcdHsync0  = 0;                                                               // Start of horizontal sync pulse
   lcdHsync1  = 48;                                                            // End of horizontal sync pulse
   lcdVcycle  = 525;                                                           // Total number of lines per screen
   lcdVoffset = 32;                                                            // Start of active screen
   lcdVsync0  = 0;                                                              // Start of vertical sync pulse
   lcdVsync1  = 3;                                                              // End of vertical sync pulse
   lcdPclk    = 2;                                                                  // Pixel Clock
   lcdSwizzle = 0;                                                              // Define RGB output pins
   lcdPclkpol = 1;                                                              // Define active edge of PCLK                 

HCYCLE = 928
VCYCLE = 525
VCYCLE * HCYCLE  = 487,200

Note: REG_PCLK is using the value 2 which will divide the clock down to 30Mhz (assuming system clock of 60Mhz).

Result = 30,000,000/487,200 = ~ 61 fps

In short, yes EVE can drive a FWVGA display, you would just achieve a slightly slower refresh rate than using a WVGA display for example.

Best Regards,
BRT community

[Rudolph]

Are you trying to upcycle a Smartphone or Beamer display?
Please provide a datasheet link to such a display.

[JeffC]

Thanks for the quick replies.
@BRT Community: If I take your example, which had a horizontal 'overhead' (porch I guess) of 128 clocks and a vertical overhead of 45 clocks, that would roughly compute to 30,000,000 / (854+128) / (45+480) = 58 Hz. That should be ok. Subject to actual display requirements of course.
@Rudolf: I was considering a 'smartphone like' display for a product development. The lack of a metal frame on the front side should allow for easy bonding to a cover glass. Longevity of supply is of course the downside.
I don't have a datasheet indicating the complete timing requirements yet. Will report back.