FPGA, SoC, And CPLD Boards And Kits
FPGA Evaluation and Development Kits
Announcements
Intel Support hours are Monday-Fridays, 8am-5pm PST, except Holidays. Thanks to our community members who provide support during our down time or before we get to your questions. We appreciate you!

Need Forum Guidance? Click here
Search our FPGA Knowledge Articles here.

De0 vga dac help

Altera_Forum
Honored Contributor II
1,056 Views

Hi, 

 

I am trying to produce a vga output to my crt. I understood the basics of timing but DE0 board's 4 bit resistor network dac confuses me. I searched over internet but I couldn't find anything helpfull. How should I use it? For example what will vga red signal "1111" produce?  

 

On manual it says to look for ADV7123 dac datasheet. How is DE0 related with ADV7123? Is there a secret dac like this on DE0 board that is not showed on schematics? 

 

I am really confused any help will be greatly appreciated. 

 

Thanks, 

isumairu
0 Kudos
1 Reply
Altera_Forum
Honored Contributor II
123 Views

I think I figured it out the DE0 board has nothing to do with ADV7123 DAC. I don't know why it is showed as a reference in manual. My experiments showed that four bit resistor network simply produce different voltage levels for each rgb signal. For example with vga_R3 pin as MSB, "0000" red signal will produce blank and "1111" red signal will produce the brightest red pattern. So each 4 bit resistor network helps the user to produce 16 different tones of a color. 

 

I just have figured out that from experiments so I have to study more about this multiple bit color subject. Please share any references that you know about this subject. 

 

thanks, 

isumairu
Reply