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Autographics mode on ADV7604

Question asked by rsun on Sep 20, 2011
Latest reply on May 26, 2017 by vefone

I'm having some difficulty getting the autographics mode on the 7604 to work properly. If I choose a video mode that matches the resolutions expected by the part, I at least get video out of it, but when I choose a non-standard mode, I get nothing. I've followed the autographics document "ADV7604_Autographics_RevPrA.pdf" but I can't seem to get things working. Our system uses the video output ports in 16 bit 4:2:2 mode with embedded sync, so I've not bothered with the configuration of DE/HS/VS/F.

 

As an example, consider receiving 1280x720p60 (CEA-861D timings) from a Mac via VGA.

 

The timing parameters for this mode are:

 

1650 horizontal pixels, 1280 active, 110 end of video to hsync, 40 in hsync, 220 end of hsync to video

750 vertical lines, 720 active, 5 lines end of video to vsync, 5 in vsync, 20 end of vsync to video

74.25mhz pixel clock, 60 frames per second

 

Following the document, I've done:

 

2.1:

IO Map(0x00) = 0x07 [Video Standard = Auto]

IO Map(0x01) = 0x02 [Primary Mode = RGB, 60Hz]

 

2.2:

IO Map(0x16/0x17) = 0x86 0x72 [PLL Manual Divisor enabled, PLL divisor set to 1650]

 

2.3:

CP Map(0x8f/0x90) = 0x02 0x7c [Channel 1 Free Run Line Length = 636 - using the 28.636mhz crystal option]

Do I need to set the equivalent registers in the Channel 2 area (CP_MAP(0x46-0x48)? - we're not using sync channel 2 for anything.

 

2.4:

CP Map(0xab/0xac) = 0x2e 0x00 [CP maximum line count = 750]

Ditto for the channel 2 equivalent

 

2.5:

CP Map(0x91) = 0x40 [Progressive expected? Note that the autographics document and "ADV7604_SW_RevF.pdf" disagree on the meaning of this bit. I've tried it both ways to no avail]

 

2.6:

Since we're not using the output HS/VS/DE/F, I've ignored this section and left the registers at the default 0 values.

 

2.7:

CP Map(0xa2-0xa4) = 0x10 0x06 0x04 [CP_START_SAV = 256, CP_START_EAV = 1540]

CP Map(0xa5-0xaa) = 2e 0xa0 0x1a 0x2e 0xa0 0x1a [CP_START_VBI = 746, CP_END_VBI = 26, + even field couterparts the same]

 

2.8:

IO_MAP(0x02) = 0x14 [Input color space = 1 (RGB 0..255)]

 

I've also tried with CP Map(0x81) bit 4 both set and cleared (auto graphics av code enable/disable) and that doesn't make a difference.

 

If I send 1024x768 and use video standard 12 instead of 7 things work correctly all else being the same. If I use a digital input, everything is fine, so I'm fairly certain that the part is configured correctly to talk to the DSP video port it's connected to.

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