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chumbyhackerboard:vga

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chumbyhackerboard:vga [2010/09/21 05:04]
ladyada
chumbyhackerboard:vga [2016/01/28 18:05] (current)
Line 19: Line 19:
 SO! SO!
  
-HW_LCDIF_VDCTRL2 = (96) << 24 | (640 + 16 + 48) = 0x600002C0+HW_LCDIF_VDCTRL2 = (96) << 24 | (640 + 16 + 96+ 48) = 0x60000320
  
 ====== Vsync HW_LCDIF_VDCTRL1 ====== ====== Vsync HW_LCDIF_VDCTRL1 ======
  
 For the LCD, this is by default = 0x0000011a (dec. 282) For the LCD, this is by default = 0x0000011a (dec. 282)
 +
 +We want...
  
   * Per vertical line: 480 horizontal lines   * Per vertical line: 480 horizontal lines
Line 30: Line 32:
   * back porch: 31 horizontal lines   * back porch: 31 horizontal lines
  
-so HW_LCDIF_VDCTRL1 = 542 (0x21e)+so HW_LCDIF_VDCTRL1 = 524 (0x20C)
  
 ====== HW_LCDIF_VDCTRL0 ====== ====== HW_LCDIF_VDCTRL0 ======
Line 58: Line 60:
  
 -> 0x00340002 -> 0x00340002
 +
 +====== HW_LCDIF_VDCTRL3 ======
 +by default = 0x004b0027
 +
 +  * MUX_SYNC_SIGNALS = 0
 +  * VSYNC_ONLY = 1 (?)
 +  * HORIZONTAL_WAIT_CNT = 48 (h back porch) + 96 (sync pulse) = 0xDE and then 
 +  * VERTICAL_WAIT_CNT = 31 (v back porch) + 2 (sync pulse) = 0x21
 +
 +-> 0x00DE0021
  
 ====== HW_LCDIF_TRANSFER_COUNT ====== ====== HW_LCDIF_TRANSFER_COUNT ======
Line 72: Line 84:
 DIV = 0x12 -> CLK of 21 Mhz DIV = 0x12 -> CLK of 21 Mhz
  
-Hmm, guess our chip isnt running at 454? Or is it our scope? Try 0x0F for 25MHz +Hmm, guess our chip isnt running at 454? Or is it our scope? Try 0x0F for 25MHz  which matches with eveything else. Which means we're running at 375MHz?
  
 ===== Results? ===== ===== Results? =====
 +PIXCLK = 0x0F
 +
 +HSync = 31.3Khz (should be 31.46)
  
-HSync 31.4Khz (should be 31.46)+Vsync 59.75 Hz (should be 60.04)
  
-Vsync = 58 Hz (should be 60.04)+Vsync negative pulse 63.9 uS (should be 63.57) (it is low from the negative edge of one HSync to another negative Hsync edge)
  
-Vsync negative pulse = 63.uS (should be 63.57) (it is low from the negative edge of one HSync to another negative Hsync edge)+Hsync negative pulse = 3.83 uS (should be 3.81)
  
-Hsync negative pulse 4.34 uS (should be 3.81)+HSync Back porch = 5 uS (should be 1.9?​), ​Hsync front porch ~14.2uS (should be 0.9?)
/home/ladyada/public_html/wiki/data/attic/chumbyhackerboard/vga.1285045464.txt.gz · Last modified: 2016/01/28 18:05 (external edit)