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ADV7513 problem running at VGA 640 x 480 input.

Question asked by mform on Feb 27, 2014
Latest reply on Mar 3, 2014 by DaveD

Hello:

 

I have been having a major problem getting the ADV7513 to output HDMI video at 640 x 480. The inputs are 24 bit (8,8,8) RGB with separate negative going HYSNC (31.25 KHz, about 4 uS wide) and VSYNC (59.6 Hz about 64 uS wide) signals at 640 x 480 P. The aspect ration is 4:3. The pixel clock is about 25 MHz.This is a computer generated signal so there is no audio or HDCP encryption.

 

I have set the registers as specified in the "Programming Quick-Start Guide". I do not read the EDID or do anything else having to do with the audio. I supply the sync signals and want to generate the DE. Register 0x41 is written to first to power on the chip.

 

The registers that I set are as follows:

 

0x15 >> 0x00 (Input ID = 0000)

0x16 >> 0x30

0x17 >> 0x61

0x35 >> 0x1e   --------| 0x35 to 0x3a from Table 26 of Programming Guide

0x36 >> 0x64               for 480p

0x37 >> 0x05

0x38 >> 0xa0

0x39 >> 0x1e

0x3a >> 0x00  ---------|

0x3b >> 0x80

0x3c >> 0x02

0x41 >> 0x12

0x56 >> 0x18

0x98 >> 0x03

0x9a >> 0xe0

0x9c >> 0x30

0x9d >> 0x61

0xa2 >> 0xa4

0xa3 >> 0xa4

0xaf >> 0x06

0xba >> 0x60

0xd0 >> 0x32

0xe0 >> 0xd0

0xf9 >> 0x00

0xfa >> 0x7d

 

All other registers are at their default values.

 

I am a bit confused as to the correct settings for 0xd7 - 0xdc. Do these have to be set as per Table 27?

The PLL shows as locked. All of the power supply voltages are correct. However, there is no video output.

 

Is there any problem people have run into using the ADV7513 as described above? Is there a problem if the input is not EXACTLY as a standard VGA signal? Am I loading any registers incorrectly or not loading some properly?

 

Any help would be appreciated as I have been trying to get some video for the last couple of weeks.

 

Thanks.

 

Mike

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