single rank vs. dual rank

[salma ali bakr]

single rank vs dual rank memory

what's the difference between single rank and dual rank DDR DIMM Module...?? how should i know if a memory is single or dual rank, when it doesn't say anything on the pamphlet attached to it nor on its site! while i have to choose between 2 projects on the digilent site, one is addressing single rank and the other one dual rank!!!!

 

[BlackOps]

single rank between dual rank memory

Hello Ali, i am also going to work with DDR SDRAM memory with XUPV2P board.. what is your purpose? what do you have?

 

[salma ali bakr]

ddr single rank vs dual rank

hi
my name is Salma not Ali
my dad's name is Ali

i just wanted to try an example of a VGA interface for this board from digilent site...there are two examples...one for 512MB single rank and the other one dual rank...i just wanted to figure out what kind of memory am i using...how can i know that...? it doesn't say on it nor in its pamphlet nor on its site...

also, i'm having trouble in another example...the software doesn't seem to enter in the main function at all and so nothing is displayed on my hyperterminal...and i don't know how to solve this...although it's an example also from xilinx and it should be working okay!

 

[BlackOps]

ram single ranked dual ranked

ok Salma

Here is a good website about XUP board, and basic examples.
https://virtex2pro.blogspot.com/

follow the first tutorial, it turns ON leds and also sends data on the hyperterminal.. if u will see LEDs On, then ur example worked on the board and u must tweak ur hyperterminal settings..

cya soon!

 

[salma ali bakr]

dual rank vs single rank

hi

guess what..? it worked...the vga example worked.. YESSSSSSSSS
i was putting the code in the DDR but it was supposed to be in the BRAM...while the data to be displayed would be in the DDR...! so it was sort of writing over itself...

and also there was something wrong with the linker script...it didn't have the .init part...so i enabled the default linker script instead of using a custom one...and this can be done in compiler options...

i saw it on XMD and it'll all fine...although its GUI isn't working and i had to start it from the command prompt :idea:

thanks a lot for the link, i'll surely open it and do as much as i can from it

as for the dual rank, i discovered that it meant having the memory on both sides of the PCB ..!!! that's all ...

and mine is dual rank

 

[BlackOps]

difference between single rank & dual rank memory

ok Salma, nice to hear it! can you say me EXACT name of the DIMM module which you used? its manufacturer? index...etc?

i did one VGA example,of generation 1024x768 video on the VGA monitor... now i want to link it to the DDR memory, and make it act as a video controller..to display any data (a C program will draw data for example..) and a system will run on PowerPC core... but i dont want to use the Digilentinc example.. and as i see its mostly Verilog... i want do all in VGA.. now i just need to figure out things about the DDR controller... it would be nice to run PLB DDR controller by Xilinx to understand first how it works..

 

[salma ali bakr]

xilinx 512mb xup dual rank ddr settings

it's from kingston , KVR266X64C25/512

512 MB 266MHz DDR PC2100 DIMM CL2.5

the digilent example is not in verilog, it's in vhdl and i've done it...it works fine

now i want to display characters on the vga monitor...by writing some C code no the PPC...but i'm somehow lost and don't know where to start...i've wrote a short code but it doesn't work or show anything on the screen..do you have any info for displaying text on the monitor..? either having the font rom done by the C code or by having it on the RAM or a ROM...etc..!!

 

[BlackOps]

xup kvr266x64c25/512

well.. i can buy:
RAM Kingston KVR400X64C25/512 512Mb DDR PC3200 CL2.5

but i think it should also work.. since PC3200 can run on 2100 also if i am not wrong..
(if i am wrong and anyone knows the reason please correct me and explan, i'd appreciate that)

regarding your next project.. i want to do almost the same.. make the C program draw lines and shapes.. and display them on VGA monitor.

i have downloaded design project file from digilentinc... i DONT see any VHDL or any other source code there. and dont see HDL folder inside.
also it gave me errors during the transition of project to the EDK 9.1.02 version...

and i think that in order to understand it better one should create such project almost from scratch...

well except that the already made DDR memory controller may be used.

also, their example displays graphics on 640x480.

i already did a working VGA interface VHDL code for 1024x768x60Hz and tested it on XUP board. now i must modify it to become the Peripheral and add it to my design, along with the already made DDR SDRAM IP from xilinx.

the cloumn and row positions will be written to the DDR memory, and the rgb data will also come from there, and that will be controlled by the C program running on PPC core. the problem is just in putting it all correctly.

i am looking and going through the examples of the website which i showed you in my first message here. that helps alot, and gives idea of how to connect the PLB bus to the PPC and your peripherals.

cya

 

[salma ali bakr]

dual rank ddr controller

in this link, all the files are in vhdl...

http://www.digilentinc.com/Products/Detail.cfm?Prod=XUPV2P&Nav1=Products&Nav2=Pr

there's a function called xtft_charcode.c in the drivers folder in the project repository....it's under the VGA TFT controller....on my pc it's D:\xilinx\lib\XilinxProcessorIP\drivers\tft_ref_v1_00_a\src
try to see it, maybe it'll help you in anyway