Merge pull request pulp-platform#276 from pulp-platform/axi_from_mem-…

…tbenz

axi_from_mem: Add `axi_lite_from_mem` and the `axi_from_mem` wrapper

Bender.yml

@@ -49,6 +49,7 @@ sources:
   - src/axi_isolate.sv
   - src/axi_join.sv
   - src/axi_lite_demux.sv
+  - src/axi_lite_from_mem.sv
   - src/axi_lite_join.sv
   - src/axi_lite_lfsr.sv
   - src/axi_lite_mailbox.sv
@@ -66,6 +67,7 @@ sources:
   - src/axi_cdc.sv
   - src/axi_err_slv.sv
   - src/axi_dw_converter.sv
+  - src/axi_from_mem.sv
   - src/axi_id_serialize.sv
   - src/axi_lfsr.sv
   - src/axi_multicut.sv

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Add `axi_channel_compare.sv`: Non-synthesizable module comparing two AXI channels of the same type
 - 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.
 
 ### Changed
 - `axi_demux`: Replace FIFO between AW and W channel by a register plus a counter.  This prevents

README.md

@@ -32,6 +32,7 @@ In addition to the documents linked in the following table, we are setting up [d
 | [`axi_dw_upsizer`](src/axi_dw_upsizer.sv)            | A data width converter between a narrow AXI master and a wider AXI slave.                            |                                |
 | [`axi_err_slv`](src/axi_err_slv.sv)                  | Always responds with an AXI decode/slave error for transactions which are sent to it.                |                                |
 | [`axi_fifo`](src/axi_fifo.sv)                        | A Fifo for each AXI4 channel to buffer requests.                                                     |                                |
+| [`axi_from_mem`](src/axi_from_mem.sv)                | This module acts like an SRAM and makes AXI4 requests downstream.                                    |                                |
 | [`axi_id_prepend`](src/axi_id_prepend.sv)            | This module prepends/strips the MSB from the AXI IDs.                                                |                                |
 | [`axi_id_remap`](src/axi_id_remap.sv)                | Remap AXI IDs from wide IDs at the slave port to narrower IDs at the master port.                    | [Doc][doc.axi_id_remap]        |
 | [`axi_id_serialize`](src/axi_id_serialize.sv)        | Reduce AXI IDs by serializing transactions when necessary.                                           | [Doc][doc.axi_id_serialize]    |
@@ -41,6 +42,7 @@ In addition to the documents linked in the following table, we are setting up [d
 | [`axi_join`](src/axi_join.sv)                        | A connector that joins two AXI interfaces.                                                           |                                |
 | [`axi_lfsr`](src/axi_lfsr.sv)                        | AXI4-attached LFSR; read returns pseudo-random data, writes are compressed into a checksum.          |                                |
 | [`axi_lite_demux`](src/axi_lite_demux.sv)            | Demultiplexes an AXI4-Lite bus from one slave port to multiple master ports.                         | [Doc](doc/axi_lite_demux.md)   |
+| [`axi_lite_from_mem`](src/axi_lite_from_mem.sv)      | This module acts like an SRAM and makes AXI4-Lite requests downstream.                               |                                |
 | [`axi_lite_join`](src/axi_lite_join.sv)              | A connector that joins two AXI-Lite interfaces.                                                      |                                |
 | [`axi_lite_lfsr`](src/axi_lite_lfsr.sv)              | AXI4-Lite-attached LFSR; read returns pseudo-random data, writes are compressed into a checksum.     |                                |
 | [`axi_lite_mailbox`](src/axi_lite_mailbox.sv)        | A AXI4-Lite Mailbox with two slave ports and usage triggered irq.                                    | [Doc](doc/axi_lite_mailbox.md) |

axi.core

@@ -31,6 +31,7 @@ filesets:
       - src/axi_isolate.sv
       - src/axi_join.sv
       - src/axi_lite_demux.sv
+      - src/axi_lite_from_mem.sv
       - src/axi_lite_join.sv
       - src/axi_lite_lfsr.sv
       - src/axi_lite_mailbox.sv
@@ -48,6 +49,7 @@ filesets:
       - src/axi_cdc.sv
       - src/axi_err_slv.sv
       - src/axi_dw_converter.sv
+      - src/axi_from_mem.sv
       - src/axi_id_serialize.sv
       - src/axi_lfsr.sv
       - src/axi_multicut.sv

src/axi_from_mem.sv

@@ -0,0 +1,124 @@
+// Copyright 2022 ETH Zurich and 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:
+// - Christopher Reinwardt <[email protected]>
+// - Nicole Narr <[email protected]
+
+`include "axi/typedef.svh"
+
+/// Protocol adapter which translates memory requests to the AXI4 protocol.
+///
+/// This module acts like an SRAM and makes AXI4 requests downstream.
+///
+/// Supports multiple outstanding requests and will have responses for reads **and** writes.
+/// Response latency is not fixed and for sure **not 1** and depends on the AXI4 memory system.
+/// The `mem_rsp_valid_o` can have multiple cycles of latency from the corresponding `mem_gnt_o`.
+module axi_from_mem #(
+  /// Memory request address width.
+  parameter int unsigned    MemAddrWidth    = 32'd0,
+  /// AXI4-Lite address width.
+  parameter int unsigned    AxiAddrWidth    = 32'd0,
+  /// Data width in bit of the memory request data **and** the Axi4-Lite data channels.
+  parameter int unsigned    DataWidth       = 32'd0,
+  /// How many requests can be in flight at the same time. (Depth of the response mux FIFO).
+  parameter int unsigned    MaxRequests     = 32'd0,
+  /// Protection signal the module should emit on the AXI4 transactions.
+  parameter axi_pkg::prot_t AxiProt         = 3'b000,
+  /// AXI4 request struct definition.
+  parameter type            axi_req_t       = logic,
+  /// AXI4 response struct definition.
+  parameter type            axi_rsp_t       = logic
+) (
+  /// Clock input, positive edge triggered.
+  input  logic                    clk_i,
+  /// Asynchronous reset, active low.
+  input  logic                    rst_ni,
+  /// Memory slave port, request is active.
+  input  logic                    mem_req_i,
+  /// Memory slave port, request address.
+  ///
+  /// Byte address, will be extended or truncated to match `AxiAddrWidth`.
+  input  logic [MemAddrWidth-1:0] mem_addr_i,
+  /// Memory slave port, request is a write.
+  ///
+  /// `0`: Read request.
+  /// `1`: Write request.
+  input  logic                    mem_we_i,
+  /// Memory salve port, write data for request.
+  input  logic [DataWidth-1:0]    mem_wdata_i,
+  /// Memory slave port, write byte enable for request.
+  ///
+  /// Active high.
+  input  logic [DataWidth/8-1:0]  mem_be_i,
+  /// Memory request is granted.
+  output logic                    mem_gnt_o,
+  /// Memory slave port, response is valid. For each request, regardless if read or write,
+  /// this will be active once for one cycle.
+  output logic                    mem_rsp_valid_o,
+  /// Memory slave port, response read data. This is forwarded directly from the AXI4-Lite
+  /// `R` channel. Only valid for responses generated by a read request.
+  output logic [DataWidth-1:0]    mem_rsp_rdata_o,
+  /// Memory request encountered an error. This is forwarded from the AXI4-Lite error response.
+  output logic                    mem_rsp_error_o,
+  /// AXI4 master port, slave aw cache signal
+  input  axi_pkg::cache_t         slv_aw_cache_i,
+  /// AXI4 master port, slave ar cache signal
+  input  axi_pkg::cache_t         slv_ar_cache_i,
+  /// AXI4 master port, request output.
+  output axi_req_t                axi_req_o,
+  /// AXI4 master port, response input.
+  input  axi_rsp_t                axi_rsp_i
+);
+
+  `AXI_LITE_TYPEDEF_ALL(axi_lite, logic [AxiAddrWidth-1:0], logic [DataWidth-1:0], logic [DataWidth/8-1:0])
+  axi_lite_req_t axi_lite_req;
+  axi_lite_resp_t axi_lite_rsp;
+
+  axi_lite_from_mem #(
+    .MemAddrWidth    ( MemAddrWidth    ),
+    .AxiAddrWidth    ( AxiAddrWidth    ),
+    .DataWidth       ( DataWidth       ),
+    .MaxRequests     ( MaxRequests     ),
+    .AxiProt         ( AxiProt         ),
+    .axi_req_t       ( axi_lite_req_t  ),
+    .axi_rsp_t       ( axi_lite_resp_t )
+  ) i_axi_lite_from_mem (
+    .clk_i,
+    .rst_ni,
+    .mem_req_i,
+    .mem_addr_i,
+    .mem_we_i,
+    .mem_wdata_i,
+    .mem_be_i,
+    .mem_gnt_o,
+    .mem_rsp_valid_o,
+    .mem_rsp_rdata_o,
+    .mem_rsp_error_o,
+    .axi_req_o       ( axi_lite_req    ),
+    .axi_rsp_i       ( axi_lite_rsp    )
+  );
+
+  axi_lite_to_axi #(
+    .AxiDataWidth    ( DataWidth       ),
+    .req_lite_t      ( axi_lite_req_t  ),
+    .resp_lite_t     ( axi_lite_resp_t ),
+    .axi_req_t       ( axi_req_t       ),
+    .axi_resp_t      ( axi_rsp_t       )
+  ) i_axi_lite_to_axi (
+    .slv_req_lite_i  ( axi_lite_req    ),
+    .slv_resp_lite_o ( axi_lite_rsp    ),
+    .slv_aw_cache_i,
+    .slv_ar_cache_i,
+    .mst_req_o       ( axi_req_o       ),
+    .mst_resp_i      ( axi_rsp_i       )
+  );
+
+endmodule