Hi all. I am using a DE2 , and I am trying to show RGB test pattern generator on the VGA. I am using vip to genereate the colour bars, but i have not benn able to fully understand the way VCO works. Can I use it to pilot the VGA output, or I need first a frame buffer or something similar? I've read all the datasheets i could, but i haven't been able to find an answer.

The VIP Test Pattern Generator and the clocked video output will do the work. The only thing is that you need to connect the Clocked video output signals to the VGA HS and VS of the VGA connector and the data, blank and sync to the D2A on the DE2 board. you can use one of the video example designs that are avalible on this forum. Goodluck, Reuven Aboudi

Thanks for your answer. I've managed to use text pattern and clocked output, no i can display color bars both in 1024*768 and 640*480. Right now, I am trying to use the frame buffer between the test pattern generator and the clocked video output, using the sdram to store pixels. I am not sure on wich clock should I use. Now, I am in trouble with the frame buffer and clocks... I am using (in 640*480) 31.5 MHz as pixel video clock, 100 MHz as test video, clocked output and frame buffer clock,finally, a 100Mhz with a -3ns delay for the SDRAM, but the system does not work. I have no DDR2 on the DE2 board, but I think that it shouldn't be necessary in order to use the FB with a 640*480 image. Any hint?

Hi again, I had difficulty to understand exactly what you have done especially the explanations about clocks. But I can recommend you that I use the Frame buffer with a different clocks for memory and video stream (the clock of all VIP components), you can this by configuring the FB to "use separate clocks for avalon-MM master interface". BR, Reuven

Well, I am tryng to use buffering for video streams in my system. To buffer an 640*480 video frame, i need at least 1.2Mb of memory, so i have to use sdram. This sdram is an SDR (the DE2 has only a 8M SDR sdram), and in a tutorial for the sdram they(Altera) say that sdram need a -3ns delay. So, my system is this:http://img62.imageshack.us/img62/7727/videotest.png (http://img62.imageshack.us/i/videotest.png/) But the output is still incorrect, and i don't know why. and If I use buffer inside the deinterlacer, I have the same troubles...

It looks like that you may have problems are with the SDRAM. From what I see I think you are working with high clock rates for both the video and memory. Your video clock is 70MHz while you need for composite input only 27MHz if the color components are parallel the VGA output (640 x 480 @ 60Hz) only need 25 MHz if the color components are parallel. 50 MHz clock for video will be OK. The SRAM clock you use is 140MHz, but I think the SDRAM controller work only up to 100MHz in Stratix devices, in other device even less. I would also suggest you to read in the SDRAM Controller document and follow the clock phase setting for the SDRAM. Good luck, Reuven

Video Clocked output and VGA | Altera Community

51 Replies

Altera_Forum
Honored Contributor
16 years ago
my fault.
reading this, http://www.altera.com/literature/hb/qts/qts_qii54006.pdf?gsa_pos=12&wt.oss_r=1&wt.oss=sdr%20sdram Altera says that
"The SDR SDRAM controller acts as a bridge between the system interconnect fabric and the pins on an SDRAM device. The SDR SDRAM controller can operate in excess of 100 MHz."
So, your considerations were rigth: we can work with SDR SDRAM up to 100MHz.
Bandwidth is different, right now: available band is 16*100mhz= 1.6gb/s
Altera_Forum
Honored Contributor
16 years ago
i used ur setting for my framebuffer..unfortunately it didnt work..i still get flickered output as shown in previous post..
http://www.alteraforum.com/forum/showpost.php?p=88736&postcount=25

here is my current setting for framebuffer..
https://www.alteraforum.com/forum/attachment.php?attachmentid=2420

I have a DE2 board as yours too..mybe i will try on it usnig ur setting and post the results here

cheers, suki
Altera_Forum
Honored Contributor
16 years ago
Did you try to set base adresses of the framebuffer at all 0?
Altera_Forum
Honored Contributor
16 years ago
--- Quote Start ---
Did you try to set base adresses of the framebuffer at all 0?
--- Quote End ---

i think that base address depends on the base address of sdram in sopc..my sdram base is at 0x02000000. Correct me if i understand it wrong..:confused:
Altera_Forum
Honored Contributor
16 years ago
I thought that base address is the offset in the sdram where data are going to be stored. 0x0s means @start from the first column, first row, etc etc etc.
0x020000000 means start from the 33554432 bit free..
Altera_Forum
Honored Contributor
16 years ago
--- Quote Start ---
I thought that base address is the offset in the sdram where data are going to be stored. 0x0s means @start from the first column, first row, etc etc etc.
0x020000000 means start from the 33554432 bit free..
--- Quote End ---

ic.. so ive misunderstood it..:D i'll try change it to 0x000000..thanks
Altera_Forum
Honored Contributor
16 years ago
one last consideration...
96
16
48

2
11
32
are the settings for VGA @ 75hz. if you want to use THIS resolution, you should set your pixel clock for the vga @ 31.5MHz

Greetings
Phate :)
Altera_Forum
Honored Contributor
16 years ago
--- Quote Start ---
ic.. so ive misunderstood it..:D i'll try change it to 0x000000..thanks
--- Quote End ---

ive change it..sumhow changing the framebuffer base address doesnt fix it..it still flicker..wonder why..
Altera_Forum
Honored Contributor
16 years ago
hem.. how many bit per color plane are you using in tp generator?
my setings are made up for 5 bit per color plane, so try to set the test pattern to generate a signal rgb 444 with 5 bits per color plane.
It should work.
Let me know
greetings
Phate
Altera_Forum
Honored Contributor
16 years ago
Just one info/help question:
It seems that in quartus2 9.1 sp1 VIP do not work well.
Anyone knows if in quartus2 9.1 sp2 any issues have been fixed?

Or, when can i find vip for 9.0 version of quartus2 9.0, if I would downgrade my current version?

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Video Clocked output and VGA

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