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

Timestamp:

Nov 30, 2011, 3:21:40 PM (13 years ago)

Author:

kallisti5

Comment:

adding Ontario / llano notes. aka hell on earth

HardwareInfo/video/RadeonHD_tech

@@ -85 +85 @@
 pixelClock = (pll reference frequency (xtal) * pll feedback divider) + (pll reference frequency (xtal) * pll's feedback divider decimal place ) / (pll's reference divider * post divider)
 }}}
+
+
+'''TRAVIS and NUTMEG external encoders'''
+{{{
+TRAVIS and NUTMEG are tricky
+they are DP to LVDS and DP to VGA bridge chips
+so you need to set up the digital encoder and transmitter and the bridge
+also, starting with dce3, there is a table called AdjustPixelClock that you need to call to calculate the proper pixel clock
+in some cases it will return hardcoded dividers or special pixel clocks
+e.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
+TRAVIS and NUTMEG are basically DP, but more complicated
+you still have to do link training, etc.
+
+Ontario (PALM, E-350, E-450) has native VGA and LVDS, but some oems use the DP bridges anyway
+llano (SUMO, SUMO2) has no native LVDS or VGA so it has to use the bridge chips
+  in this case, there will be two encoders associated with the LVDS or VGA connector
+  a UNIPHY/1/2 and NUTMEG or TRAVIS
+if there is no external encoder, it's just regular LVDS
+also, DP uses aux rather than i2c for DDC
+the 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
+so you have to check if the attached monitor is DP or TMDS, then use aux or i2c to read the EDID
+}}}