Hi:

check that...

Please see the below link

http://www.xilinx.com/support/documentation/data_sheets/ds099.pdf

MicroBlaze is a soft processor that gets implemented in the FPGA fabric. You can implement as many MicroBlaze cores as you can in every Xilinx FPGA.

In the Spartan3 200 you only have 4300 logic cells, which will be just enough for one core plus some peripherals but not more.

The Microblaze reference Guide is the UG081:

http://www.xilinx.com/support/documentation/sw_manuals/xilinx13_1/mb_ref_guide.pdf

Hope that will help you.

Regards

Olivier