Merge pull request pulp-platform#277 from pulp-platform/axi_rw_join_s…

…plit-tbenz

Add rw_split and rw_join modules

Bender.yml

@@ -59,6 +59,8 @@ sources:
   - src/axi_lite_to_axi.sv
   - src/axi_modify_address.sv
   - src/axi_mux.sv
+  - src/axi_rw_join.sv
+  - src/axi_rw_split.sv
   - src/axi_serializer.sv
   - src/axi_slave_compare.sv
   - src/axi_throttle.sv

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Add `axi_bus_compare` and `axi_slave_compare`; two synthesizable verification IPs meant to be used
   to compare two AXI buses on an FPGA.
 - Add `axi_lite_from_mem` and `axi_from_mem` acting like SRAMs making AXI4 requests downstream.
+- Add `axi_rw_join` and `axi_rw_split` to split/join AXI buses.
 
 ### Changed
 - `axi_demux`: Replace FIFO between AW and W channel by a register plus a counter.  This prevents

README.md

@@ -55,6 +55,8 @@ In addition to the documents linked in the following table, we are setting up [d
 | [`axi_multicut`](src/axi_multicut.sv)                | AXI register which can be used to relax timing pressure on long AXI buses.                           |                                |
 | [`axi_mux`](src/axi_mux.sv)                          | Multiplexes the AXI4 slave ports down to one master port.                                            | [Doc](doc/axi_mux.md)          |
 | [`axi_pkg`](src/axi_pkg.sv)                          | Contains AXI definitions, common structs, and useful helper functions.                               |                                |
+| [`axi_rw_join`](src/axi_rw_join.sv)                  | Joins a read and a write slave into one single read / write master.                                  |                                |
+| [`axi_rw_split`](src/axi_rw_split.sv)                | Splits a single read / write slave into one read and one write master.                               |                                |
 | [`axi_serializer`](src/axi_serializer.sv)            | Serializes transactions with different IDs to the same ID.                                           |                                |
 | [`axi_throttle`](src/axi_throttle.sv)                | Limits the maximum number of outstanding transfers sent to the downstream logic.                     |                                |
 | [`axi_test`](src/axi_test.sv)                        | A set of testbench utilities for AXI interfaces.                                                     |                                |

axi.core

@@ -41,6 +41,8 @@ filesets:
       - src/axi_lite_to_axi.sv
       - src/axi_modify_address.sv
       - src/axi_mux.sv
+      - src/axi_rw_join.sv
+      - src/axi_rw_split.sv
       - src/axi_serializer.sv
       - src/axi_slave_compare.sv
       - src/axi_throttle.sv

src/axi_rw_join.sv

@@ -0,0 +1,110 @@
+// Copyright (c) 2022 ETH Zurich, University of Bologna
+//
+// Copyright and related rights are licensed under the Solderpad Hardware
+// License, Version 0.51 (the "License"); you may not use this file except in
+// compliance with the License.  You may obtain a copy of the License at
+// http://solderpad.org/licenses/SHL-0.51. Unless required by applicable law
+// or agreed to in writing, software, hardware and materials distributed under
+// this License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+//
+// Authors:
+// - Tobias Senti <[email protected]>
+
+`include "axi/assign.svh"
+`include "common_cells/assertions.svh"
+
+/// Joins a read and a write slave into one single read / write master
+///
+/// Connects the ar and r channel of the read slave to the read / write master
+/// and the aw, w and b channel of the write slave to the read / write master
+module axi_rw_join #(
+  parameter type axi_req_t  = logic,
+  parameter type axi_resp_t = logic
+) (
+  input  logic      clk_i,
+  input  logic      rst_ni,
+  // Read Slave
+  input  axi_req_t  slv_read_req_i,
+  output axi_resp_t slv_read_resp_o,
+
+  // Write Slave
+  input  axi_req_t  slv_write_req_i,
+  output axi_resp_t slv_write_resp_o,
+
+  // Read / Write Master
+  output axi_req_t  mst_req_o,
+  input  axi_resp_t mst_resp_i
+);
+
+  //--------------------------------------
+  // Read channel data
+  //--------------------------------------
+
+  // Assign Read Structs
+  `AXI_ASSIGN_AR_STRUCT ( mst_req_o.ar       , slv_read_req_i.ar  )
+  `AXI_ASSIGN_R_STRUCT  ( slv_read_resp_o.r  , mst_resp_i.r       )
+
+  // Read B channel data
+  assign slv_read_resp_o.b         = '0;
+
+
+  //--------------------------------------
+  // Read channel handshakes
+  //--------------------------------------
+
+  // Read AR channel handshake
+  assign mst_req_o.ar_valid        = slv_read_req_i.ar_valid;
+  assign slv_read_resp_o.ar_ready  = mst_resp_i.ar_ready;
+
+  // Read R channel handshake
+  assign slv_read_resp_o.r_valid   = mst_resp_i.r_valid;
+  assign mst_req_o.r_ready         = slv_read_req_i.r_ready;
+
+  // Read AW, W and B handshake
+  assign slv_read_resp_o.aw_ready  = 1'b0;
+  assign slv_read_resp_o.w_ready   = 1'b0;
+  assign slv_read_resp_o.b_valid   = 1'b0;
+
+  // check for AW and W never to be valid
+  `ASSERT_NEVER(slv_read_req_aw_valid, slv_read_req_i.aw_valid, clk_i, !rst_ni)
+  `ASSERT_NEVER(slv_read_req_w_valid,  slv_read_req_i.w_valid,  clk_i, !rst_ni)
+
+  //--------------------------------------
+  // Write channel data
+  //--------------------------------------
+
+  // Assign Write Structs
+  `AXI_ASSIGN_AW_STRUCT ( mst_req_o.aw       , slv_write_req_i.aw )
+  `AXI_ASSIGN_W_STRUCT  ( mst_req_o.w        , slv_write_req_i.w  )
+  `AXI_ASSIGN_B_STRUCT  ( slv_write_resp_o.b , mst_resp_i.b       )
+
+  // Write R channel data
+  assign slv_write_resp_o.r        = '0;
+
+
+  //--------------------------------------
+  // Write channel handshakes
+  //--------------------------------------
+
+  // Write AR and R channel handshake
+  assign slv_write_resp_o.ar_ready = 1'b0;
+  assign slv_write_resp_o.r_valid  = 1'b0;
+
+  // check for AR to never be valid
+  `ASSERT_NEVER(slv_write_req_ar_valid, slv_write_req_i.ar_valid, clk_i, !rst_ni)
+
+  // Write AW channel handshake
+  assign mst_req_o.aw_valid        = slv_write_req_i.aw_valid;
+  assign slv_write_resp_o.aw_ready = mst_resp_i.aw_ready;
+
+  // Write W channel handshake
+  assign mst_req_o.w_valid         = slv_write_req_i.w_valid;
+  assign slv_write_resp_o.w_ready  = mst_resp_i.w_ready;
+
+  // Write B channel handshake
+  assign slv_write_resp_o.b_valid  = mst_resp_i.b_valid;
+  assign mst_req_o.b_ready         = slv_write_req_i.b_ready;
+
+endmodule : axi_rw_join

src/axi_rw_split.sv

@@ -0,0 +1,111 @@
+// Copyright (c) 2022 ETH Zurich, University of Bologna
+//
+// Copyright and related rights are licensed under the Solderpad Hardware
+// License, Version 0.51 (the "License"); you may not use this file except in
+// compliance with the License.  You may obtain a copy of the License at
+// http://solderpad.org/licenses/SHL-0.51. Unless required by applicable law
+// or agreed to in writing, software, hardware and materials distributed under
+// this License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+// CONDITIONS OF ANY KIND, either express or implied. See the License for the
+// specific language governing permissions and limitations under the License.
+//
+// Authors:
+// - Tobias Senti <[email protected]>
+
+`include "axi/assign.svh"
+`include "common_cells/assertions.svh"
+
+/// Splits a single read / write slave into one read and one write master
+///
+/// Connects the ar and r channel of the read / write slave to the read master
+/// and the aw, w and b channel of the read / write slave to the write master
+module axi_rw_split #(
+  parameter type axi_req_t  = logic,
+  parameter type axi_resp_t = logic
+) (
+  input  logic      clk_i,
+  input  logic      rst_ni,
+  // Read / Write Slave
+  input  axi_req_t  slv_req_i,
+  output axi_resp_t slv_resp_o,
+
+  // Read Master
+  output axi_req_t  mst_read_req_o,
+  input  axi_resp_t mst_read_resp_i,
+
+  // Write Master
+  output axi_req_t  mst_write_req_o,
+  input  axi_resp_t mst_write_resp_i
+);
+
+  //--------------------------------------
+  // Read channel data
+  //--------------------------------------
+
+  // Assign Read channel structs
+  `AXI_ASSIGN_AR_STRUCT ( mst_read_req_o.ar  , slv_req_i.ar       )
+  `AXI_ASSIGN_R_STRUCT  ( slv_resp_o.r       , mst_read_resp_i.r  )
+
+  // Read AW and W channel data
+  assign mst_read_req_o.aw        = '0;
+  assign mst_read_req_o.w         = '0;
+
+
+  //--------------------------------------
+  // Read channel handshakes
+  //--------------------------------------
+
+  // Read AR channel handshake
+  assign mst_read_req_o.ar_valid  = slv_req_i.ar_valid;
+  assign slv_resp_o.ar_ready      = mst_read_resp_i.ar_ready;
+
+  // Read R channel handshake
+  assign slv_resp_o.r_valid       = mst_read_resp_i.r_valid;
+  assign mst_read_req_o.r_ready   = slv_req_i.r_ready;
+
+  // Read AW, W and B handshake
+  assign mst_read_req_o.aw_valid  = 1'b0;
+  assign mst_read_req_o.w_valid   = 1'b0;
+  assign mst_read_req_o.b_ready   = 1'b0;
+
+  // check for B never to be valid
+  `ASSERT_NEVER(mst_read_resp_b_valid, mst_read_resp_i.b_valid, clk_i, !rst_ni)
+
+
+  //--------------------------------------
+  // Write channel data
+  //--------------------------------------
+
+  // Assign Write channel structs
+  `AXI_ASSIGN_AW_STRUCT ( mst_write_req_o.aw , slv_req_i.aw       )
+  `AXI_ASSIGN_W_STRUCT  ( mst_write_req_o.w  , slv_req_i.w        )
+  `AXI_ASSIGN_B_STRUCT  ( slv_resp_o.b       , mst_write_resp_i.b )
+
+  // Write AR channel data
+  assign mst_write_req_o.ar       = '0;
+
+
+  //--------------------------------------
+  // Write channel handshakes
+  //--------------------------------------
+
+  // Write AR and R channel handshake
+  assign mst_write_req_o.ar_valid = 1'b0;
+  assign mst_write_req_o.r_ready  = 1'b0;
+
+  // check for R never to be valid
+  `ASSERT_NEVER(mst_read_resp_r_valid, mst_read_resp_i.r_valid, clk_i, !rst_ni)
+
+  // Write AW channel handshake
+  assign mst_write_req_o.aw_valid = slv_req_i.aw_valid;
+  assign slv_resp_o.aw_ready      = mst_write_resp_i.aw_ready;
+
+  // Write W channel handshake
+  assign mst_write_req_o.w_valid  = slv_req_i.w_valid;
+  assign slv_resp_o.w_ready       = mst_write_resp_i.w_ready;
+
+  // Write B channel handshake
+  assign slv_resp_o.b_valid       = mst_write_resp_i.b_valid;
+  assign mst_write_req_o.b_ready  = slv_req_i.b_ready;
+
+endmodule : axi_rw_split

src/axi_to_mem_split.sv

@@ -81,27 +81,19 @@ module axi_to_mem_split #(
 
   logic read_busy, write_busy;
 
-  always_comb begin: proc_axi_rw_split
-    `AXI_SET_R_STRUCT(axi_resp_o.r, axi_read_resp.r)
-    axi_resp_o.r_valid     = axi_read_resp.r_valid;
-    axi_resp_o.ar_ready    = axi_read_resp.ar_ready;
-    `AXI_SET_B_STRUCT(axi_resp_o.b, axi_write_resp.b)
-    axi_resp_o.b_valid     = axi_write_resp.b_valid;
-    axi_resp_o.aw_ready    = axi_write_resp.aw_ready;
-    axi_resp_o.w_ready     = axi_write_resp.w_ready;
-
-    axi_write_req = '0;
-    `AXI_SET_AW_STRUCT(axi_write_req.aw, axi_req_i.aw)
-    axi_write_req.aw_valid = axi_req_i.aw_valid;
-    `AXI_SET_W_STRUCT(axi_write_req.w, axi_req_i.w)
-    axi_write_req.w_valid = axi_req_i.w_valid;
-    axi_write_req.b_ready = axi_req_i.b_ready;
-
-    axi_read_req = '0;
-    `AXI_SET_AR_STRUCT(axi_read_req.ar, axi_req_i.ar)
-    axi_read_req.ar_valid = axi_req_i.ar_valid;
-    axi_read_req.r_ready  = axi_req_i.r_ready;
-  end
+  axi_rw_split #(
+    .axi_req_t  ( axi_req_t  ),
+    .axi_resp_t ( axi_resp_t )
+  ) i_axi_rw_split (
+    .clk_i,
+    .rst_ni,
+    .slv_req_i        ( axi_req_i        ),
+    .slv_resp_o       ( axi_resp_o       ),
+    .mst_read_req_o   ( axi_read_req     ),
+    .mst_read_resp_i  ( axi_read_resp    ),
+    .mst_write_req_o  ( axi_write_req    ),
+    .mst_write_resp_i ( axi_write_resp   )
+  );
 
   assign busy_o = read_busy || write_busy;
 

src_files.yml

@@ -40,6 +40,8 @@ axi:
     - src/axi_lite_to_axi.sv
     - src/axi_modify_address.sv
     - src/axi_mux.sv
+    - src/axi_rw_join.sv
+    - src/axi_rw_split.sv
     - src/axi_serializer.sv
     - src/axi_slave_compare.sv
     - src/axi_throttle.sv