AM572x support for 4k HDMI output

EDIT July 15, 2016: Looks like there is some limited capability as Manisha describes later...

YiCheng,

Yes, Rogerio is correct that 4Kx4K resolution is doable by AM57x device. While saying that, one need to keep in mind following limitations -

1. Pixel clock- Max pixel clock determine how fast the PHY and output interface can transmit data. In the AM572x case, the maximum throughput is defined by the PHY running at 1.86Gbps. This could mean for 8-bit/color RGB output at 186MHz. The three R, G and B data line clocking at 186 MHz translates to 4kx4k ar 11 fps. So, while AM57x supports 4kx4k output,  max supported framerate is not 60 fps but  ~11 fps. 

2. DSS internal line buffer limitation- DSS has following 3 sets of configuration registers that configure the max size at different stages of the DSS pipeline:

      DISPC_<VID#>_PICTURE_SIZE :  MEMSIZE, MEMSIZEY  -> these define the num of pixels and lines to fetch from the memory  (DMA)

      DISPC_<GFX/VID#>_SIZE :  SIZEX , SIZEY  ->  these define the layer windows fed to the OVERLAY manager (blending)   (Input to Overlay manager)

      DISPC_SIZE_<TV/LCD#>   LPP, PPL ->  these define the final output display resolution (LPP – lines per panel, Pixels per panel)

   For the first two set of registers, horizontal parameters are 11-bits only  =>  max size = 2048  (note: cfg +1) pixels wide

   The panel size parameter are 12-bits => max_size = 4096

   With above information, maximum source window size is 2048x4096 but the output from overlay manager can be 4096x4096. As a workaround on input buffer width limitation of 2048, one can split the the 4kx4k to two 2kx4k and feed them separately over two video/gpx input pipeline to the overlay manager  for composing it as one single 4kx4k res output. 

Hope this clarifies.