I have downloaded the protocol specification v2.0 of AXI from the arm website but when i simulate them in Aldec-HDL it shows multiple errors because it is not able to open the file std_ovl_defines.h , your suggestion please ....

Looks like you need to install the open Verifiction Library

http://www.accellera.org/activities/ovl/

I downloaded the ovl library from the source you mentioned , However i still encounter some problems -

1 The extension of the file "std_ovl_v2p5_July232010" is TGZ which by default opens in CAM350 but I don't have a full version of CAM , so i tried to unzip the files then it shows the following errors -
-cannot open (psl05)
-symbolic link points to missing file
-cannot create Libi

2 Somehow an unzipped folder is created ( I guess with some files missing ) , but to add a library in Aldec-HDL , it must be in .lib format but the files in the unzipped folder are in the .vlib format

your suggestions please ..

When i searched in the "Vlib" folder of active-hdl , i found that it already had the ovl library but there are 264 errors i encounter while simulating axi protocol , the basic problems lies in the first 2 errors -
# Error: VCP1000 abc.v : (296, 4): Cannot open file: Axi.v
# Error: VCP1000 abc.v : (790, 1): Cannot open file: std_ovl_defines.h

i have the axi file as well as the file you asked me to download , but how to add these files is what i am unaware of .

I don't know your simulator, look for some setting for paths to libraries or includes or something to add these files to (with path to them of course). While the simulator may come with an ovl kit, that doesn't necessarily mean that all projects by default are set to link with it. The simulator probably just doesn't know that these files are where they are on your disk.

You downloaded a wrong protocol specification v2.0 of AXI that's why it causes an error when you try using it. Try to download a different one and see if will gonna work. Just choose the correct protocol.