Hi All ....Any idea regarding this issue while RTL simulation in caravel integration

A bit hard to debug without knowing what

ring_counter_tb

is doing.

@sangamanath : Testbench lines 33 and 34:

assign mprj_io_0[3:0] = mprj_io[11:8];
	assign mprj_io[11]=mprj_io_1;

You are treating

mprj_io[11]

as both an output (line 33) and an input (line 34). Which is it? Your configuration in the C code has GPIO 8-11 all set as user project outputs, so what is the point of trying to set

mprj_io[11]

to value 1 in the simulation? Your output "MPRJ-IO state =" from the testbench is only printing out the state of the first 8 GPIOs, which doesn't include your project outputs. So you can't tell anything from that output. Chances are that if there is a single error here, it's that you have a conflict with two drivers on

mprj_io[11]

, so the value could be indeterminate, and if so, your testbench can never pass the checks for the value in

mprj_io[11:8]

.

in ring_counter.c