SOC1-167: Added default slave in case of no expansion region define

system/src/verilog/nanosoc_chip.v

@@ -863,6 +863,19 @@ nanosoc_exp #(.ADDRWIDTH(29)
   .ip_data_req (exp_ip_req),
   .op_data_req (exp_op_req)
 );
+`else
+ // Default slave - if no expansion region
+ cmsdk_ahb_default_slave u_ahb_exp (
+   .HCLK         (HCLK),
+   .HRESETn      (HRESETn),
+   .HSEL         (HSEL_exp),
+   .HTRANS       (HTRANS_exp),
+   .HREADY       (HREADYMUX_exp),
+   .HREADYOUT    (HREADYOUT_exp),
+   .HRESP        (HRESP_exp)
+);
+ assign   HRDATA_exp = 32'heaedeaed; // Tie off Expansion Address Expansion Data
+ 
 `endif
 
 //   soclabs_ahb_aes128_ctrl u_exp_aes128 (