axi_xbar: Add pipeline stages in cross

CHANGELOG.md

@@ -327,7 +327,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
                Prevents AWs to be emmitted downstream to a different master port as long as Ws
                are still in flight to another. This prevents deadlock, if there is stalling
                downstream.
-
+- `axi_xbar`: Add parameter `PipelineStages` to `axi_pkg::xbar_cfg_t`. This adds `axi_multicuts`
+              in the crossed connections in the xbar between the demuxes and muxes.
 
 ### Fixed
 - `axi_demux`: Break combinatorial simulation loop.

src/axi_pkg.sv

@@ -399,6 +399,7 @@ package axi_pkg;
     int unsigned   MaxSlvTrans;
     bit            FallThrough;
     xbar_latency_e LatencyMode;
+    int unsigned   PipelineStages;
     int unsigned   AxiIdWidthSlvPorts;
     int unsigned   AxiIdUsedSlvPorts;
     bit            UniqueIds;

src/axi_xbar.sv

@@ -204,8 +204,23 @@ import cf_math_pkg::idx_width;
   for (genvar i = 0; i < Cfg.NoSlvPorts; i++) begin : gen_xbar_slv_cross
     for (genvar j = 0; j < Cfg.NoMstPorts; j++) begin : gen_xbar_mst_cross
       if (Connectivity[i][j]) begin : gen_connection
-        assign mst_reqs[j][i]  = slv_reqs[i][j];
-        assign slv_resps[i][j] = mst_resps[j][i];
+        axi_multicut #(
+          .NoCuts    ( Cfg.PipelineStages ),
+          .aw_chan_t ( slv_aw_chan_t      ),
+          .w_chan_t  ( w_chan_t           ),
+          .b_chan_t  ( slv_b_chan_t       ),
+          .ar_chan_t ( slv_ar_chan_t      ),
+          .r_chan_t  ( slv_r_chan_t       ),
+          .req_t     ( slv_req_t          ),
+          .resp_t    ( slv_resp_t         )
+        ) i_axi_multicut_xbar_pipeline (
+          .clk_i,
+          .rst_ni,
+          .slv_req_i  ( slv_reqs[i][j]  ),
+          .slv_resp_o ( slv_resps[i][j] ),
+          .mst_req_o  ( mst_reqs[j][i]  ),
+          .mst_resp_i ( mst_resps[j][i] )
+        );
 
       end else begin : gen_no_connection
         assign mst_reqs[j][i] = '0;