@samarth jain: There's at least one testbench (la_test2.c in caravel_user_project) that has:

// Configure All LA probes as inputs to the cpu
        reg_la0_oenb = reg_la0_iena = 0x00000000;    // [31:0]
        reg_la1_oenb = reg_la1_iena = 0x00000000;    // [63:32]
        reg_la2_oenb = reg_la2_iena = 0x00000000;    // [95:64]
        reg_la3_oenb = reg_la3_iena = 0x00000000;    // [127:96]

I am not sure if that tesbench is correct: It pre-dates the most recent version of caravel and the cocotb tests; plus, it is somewhat misleading because the

oenb

signals are independent outputs and have nothing to do with the input side. But I think the

iena

bits have to be set to zero to enable inputs from the user project to be seen by the CPU.