can't read load memory contents

Hello there, one of new members around here.

I've got a problem while i try to retrieve/pass over some values to
memory. I use EDK 9.1 and a system of microblaze, opb bus and opb bram
memory.
I try to retrieve some values from memory through a vhdl testbench,
which is port mapped in the PORT B of Bram (by making Bram's PORT B
external) and then write back these contents in other blocks - after
some processing.
I use Eclipse SDK 9.1 for that and write the following code (load and
store instructions) within a loop:

 asm(" lwi r8,r8,0x7a810001 ");
 asm(" sw r8,r8(r8) ");

I don't seem to get the contents of 0x7a810001 address (which is
'bbbbbbbb' - given by vhdl testbench) into the simulation outcome.
Is there sth wrong with the use of instructions? Should i use an OR/
ORI as well? Any problems with 16 or 32 bit values?

Thank you very much guys in advance!