Changes between Version 4 and Version 5 of HardwareInfo/video/RadeonHD_tech

Nov 30, 2011, 3:21:40 PM (8 years ago)

adding Ontario / llano notes. aka hell on earth


  • HardwareInfo/video/RadeonHD_tech

    v4 v5  
    8585pixelClock = (pll reference frequency (xtal) * pll feedback divider) + (pll reference frequency (xtal) * pll's feedback divider decimal place ) / (pll's reference divider * post divider)
     89'''TRAVIS and NUTMEG external encoders'''
     91TRAVIS and NUTMEG are tricky
     92they are DP to LVDS and DP to VGA bridge chips
     93so you need to set up the digital encoder and transmitter and the bridge
     94also, starting with dce3, there is a table called AdjustPixelClock that you need to call to calculate the proper pixel clock
     95in some cases it will return hardcoded dividers or special pixel clocks
     96e.g., for clocks less than 60 mhz (IIRC), on dce3+ cards, you need to set the pixel clock to double the requested clock rate.  then there is a special secondary divider that will split it back to the 1/2 rate
     97TRAVIS and NUTMEG are basically DP, but more complicated
     98you still have to do link training, etc.
     100Ontario (PALM, E-350, E-450) has native VGA and LVDS, but some oems use the DP bridges anyway
     101llano (SUMO, SUMO2) has no native LVDS or VGA so it has to use the bridge chips
     102  in this case, there will be two encoders associated with the LVDS or VGA connector
     103  a UNIPHY/1/2 and NUTMEG or TRAVIS
     104if there is no external encoder, it's just regular LVDS
     105also, DP uses aux rather than i2c for DDC
     106the tricky part is, DP is backwards compatible with tmds, so the ddc pads can run in i2c or aux mode depending on what type of monitor is connected
     107so you have to check if the attached monitor is DP or TMDS, then use aux or i2c to read the EDID