// assign pad_plic_int_vld = {{ 144 - 40{1'b0}}, xx_intc_vld[39:0]};
assign pad_plic_int_vld[ 39 : 0] = xx_intc_vld[ 39 : 0];
assign pad_plic_int_vld[144 - 1 : 32] = 'h0;
This is the code from openc910\smart_run\logical\common\cpu_sub_system_axi.v, the 39bit to32bit of pad_plic_int_vld的39到32bit is assigned two times.