microblaze with FSL

I have used sysgen to build a model with microblaze, but i don't know the
difference between the two functions: microblaze_nbwrite_datafsl and
microblaze_bwrite_datafsl. Will the later function stop the microblaze
until finishing writing operation? thanks.
moreover, can i debug my c source code of microblaze in sysgen? if so,
how?

microblaze_nbwrite_datafsl = non blocking write
microblaze_bwrite_datafsl = blocking write

On a non-blocking write the processor sets the control bit if the fsl
bus is full. On a blocking write the processor waits until the FSL bus
has space. More details can be obtained from the documentation (look
for the put instruction and its variants).

/Siva
Xilinx, Inc.

thanks