Displays an image in the XS Board RAM on a VGA monitor

you can download xilinx sdram controller here- ftp://ftp.xilinx.com/pub/applications/xapp/xapp134_vhdl.zip and tune it to your requirement.

Well, it would take a lot of tuning to access SRAM with an SDRAM controller. ;-)

Kolja Sulimma

"greenplanet" wrote in news: snipped-for-privacy@l41g2000cwc.googlegroups.com:

I assume you are actually referring to the SDRAM on the XSA Board and not the internal block SRAMs of the FPGA. The VGA generator design files archive

already includes an example where the VGA generator is connected to the XESS SDRAM controller so it can display images stored in the SDRAM. You can use the GXSLOAD utility to download images to the SDRAM. And you can use the img2xes utility to convert commonly-used image files into a format that GXSLOAD can handle.

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Dave Van den Bout
XESS Corp.
PO Box 33091
Raleigh NC 27636
Phn: (919) 363-4695
Fax: (801) 749-6501
devb@xess.com
http://www.xess.com

Thanks for the replies.

What I meant is the SRAM on the XS40 board, so the vga generator example for XS40 works the same way as the one for XSA board? The img2xes utility works for XS40 too? What if I actually have a bunch of data (put them all together would make an image I suppose), how should I store the data to the SRAM? I would also have to modify the vga generator example since it always sets web = '1'?

"greenplanet" wrote in news: snipped-for-privacy@f14g2000cwb.googlegroups.com:

No, the XSA VGA generator fetches image data from 16-bit SDRAM so it has to account for the variable arrival time of the data with a FIFO. The XS40 has a static 8-bit RAM with a fixed access time so the FIFO isn't needed and the image path is narrower.

The

img2xes just translates the format of common image files into the simple XES format. The XES file can be downloaded into the XS40 SRAM using the GXSLOAD utility. You should be able to use the img2xes options to format the image data for the byte-wide SRAM on the XS40.

For writing to the SRAM:

1) Lower the RAM chip-enable and raise the output-enable. 2) Output the address and data. 3) Pulse the write-enable low and then high.

You will have to modify the VGA generator to make it release the RAM address, data and control pins while you do the write operations.

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----------------------------------------------------------------
Dave Van den Bout
XESS Corp.
PO Box 33091
Raleigh NC 27636
Phn: (919) 363-4695
Fax: (801) 749-6501
devb@xess.com
http://www.xess.com

HI, I just also do the same work. I have the same problem. And have yo resolve the problem? I would like to discuss it with you! Hier is my emai address: qingwang snipped-for-privacy@hotmail.com.

"qtommy" schrieb im Newsbeitrag news:O-SdnWCndoFhB1beRVn snipped-for-privacy@giganews.com...

The xess demo only reads from the SDRAM, for write access you need to make some statemachine based arbiter that will allow write access the SDRAM, there is no demo for that unfortunatly, I did a quick dirty thing once it only wrote a small image from camera in the SDRAM

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Antti Lukats
http://www.xilant.com

Actually, this is no longer true. We have a new VGA generator application that allows the image data to be updated in the SDRAM while the VGA generator is operating

This is done using a dual-port module that fits onto our SDRAM controller and allows you to have multiple, independent channels in and out of the external SDRAM.

schrieb im Newsbeitrag news: snipped-for-privacy@o13g2000cwo.googlegroups.com...

sorry, I did not know - it does pay off to look at XESS website from time to time to get new stuff!!

independant channel support is really nice thing to have