[membkdr] Provide a tile adapter to access internal rows

Signed-off-by: Robert Schilling <[email protected]>

hw/dv/sv/mem_bkdr_util/mem_bkdr_util.core

@@ -21,6 +21,7 @@ filesets:
     files:
       - sram_scrambler_pkg.sv
       - mem_bkdr_util_pkg.sv
+      - mem_bkdr_util_row_adapter.sv: {is_include_file: true}
       - mem_bkdr_util.sv: {is_include_file: true}
       - mem_bkdr_util__rom.sv: {is_include_file: true}
       - mem_bkdr_util__sram.sv: {is_include_file: true}

hw/dv/sv/mem_bkdr_util/mem_bkdr_util.sv

@@ -2,6 +2,8 @@
 // Licensed under the Apache License, Version 2.0, see LICENSE for details.
 // SPDX-License-Identifier: Apache-2.0
 
+`include "mem_bkdr_util_row_adapter.sv"
+
 // Provides a mechanism to manipulate and access a memory instance in the design via backdoor.
 //
 // This is a class based implementation, which on initialization (`new()`) takes the path to the
@@ -35,6 +37,10 @@ class mem_bkdr_util extends uvm_object;
   // Indicates the error detection scheme implemented for this memory.
   protected err_detection_e err_detection_scheme = ErrDetectionNone;
 
+  // Adapter to access the underlying memory organization
+  // Integrators can provide a custom row adapter for their SRAM primitives
+  protected mem_bkdr_util_row_adapter row_adapter;
+
   // Convenience macro to check if ECC / parity is enabled.
   `define HAS_ECC (!(err_detection_scheme inside {ErrDetectionNone, ParityEven, ParityOdd}))
   `define HAS_PARITY (err_detection_scheme inside {ParityEven, ParityOdd})
@@ -84,6 +90,9 @@ class mem_bkdr_util extends uvm_object;
   //
   // Optional arguments:
   //
+  //   row_adapter            Adapter to access the internal row of a memory. Integrators can
+  //                          provide a custom adapter for a different memory architecture.
+  //
   //  num_prince_rounds_half   The number of rounds of PRINCE used to scramble the memory. This is
   //                           used for scrambled memories. This defaults to 3.
   //
@@ -104,20 +113,28 @@ class mem_bkdr_util extends uvm_object;
   //                           memory.
   function new(string name = "", string path, int unsigned depth,
                longint unsigned n_bits, err_detection_e err_detection_scheme,
+               mem_bkdr_util_row_adapter row_adapter = null,
                uint32_t num_prince_rounds_half = 3,
                uint32_t extra_bits_per_subword = 0, uint32_t system_base_addr = 0,
                string tiling_path = "", uint32_t tile_depth = depth);
     super.new(name);
     `DV_CHECK_FATAL(!(n_bits % depth), "n_bits must be divisible by depth.")
 
-    this.path                  = path;
-    this.tiling_path           = tiling_path;
-    this.depth                 = depth;
-    this.tile_depth            = tile_depth;
-    this.width                 = n_bits / depth;
-    this.err_detection_scheme  = err_detection_scheme;
+    this.path                   = path;
+    this.tiling_path            = tiling_path;
+    this.row_adapter            = row_adapter;
+    this.depth                  = depth;
+    this.tile_depth             = tile_depth;
+    this.width                  = n_bits / depth;
+    this.err_detection_scheme   = err_detection_scheme;
     this.num_prince_rounds_half = num_prince_rounds_half;
 
+    if (row_adapter) begin
+      this.row_adapter = row_adapter;
+    end else begin
+      this.row_adapter = new();
+    end
+
     // Check if the inferred path to each tile (or the whole memory) really exist
     for (int i = 0; i < (depth + tile_depth - 1) / tile_depth; i++) begin
       string full_path = get_full_path(i);
@@ -290,6 +307,7 @@ class mem_bkdr_util extends uvm_object;
     index    = addr >> addr_lsb;
     ram_tile = index / tile_depth;
     res      = uvm_hdl_read($sformatf("%0s[%0d]", get_full_path(ram_tile), index), data);
+    data     = row_adapter.read_row(data);
     `DV_CHECK_EQ(res, 1, $sformatf("uvm_hdl_read failed at index %0d", index))
     return data;
   endfunction
@@ -403,6 +421,7 @@ class mem_bkdr_util extends uvm_object;
     if (!check_addr_valid(addr)) return;
     index    = addr >> addr_lsb;
     ram_tile = index / tile_depth;
+    data     = row_adapter.write_row(data);
     res      = uvm_hdl_deposit($sformatf("%0s[%0d]", get_full_path(ram_tile), index), data);
     `DV_CHECK_EQ(res, 1, $sformatf("uvm_hdl_deposit failed at index %0d", index))
   endfunction
@@ -455,9 +474,14 @@ class mem_bkdr_util extends uvm_object;
 
   // this is used to write 32bit of data plus 7 raw integrity bits.
   virtual function void write39integ(bit [bus_params_pkg::BUS_AW-1:0] addr, logic [38:0] data);
+    uvm_hdl_data_t rw_data;
     `_ACCESS_CHECKS(addr, 32) // this is essentially an aligned 32bit access.
     if (!check_addr_valid(addr)) return;
-    write(addr, data);
+    // Perform a read-modify-write to access the underlying memory architecture
+    rw_data = read(addr);
+    rw_data = row_adapter.access_row_data39(addr, data, rw_data);
+    // Note the write function takes care of interleaving, if used.
+    write(addr, rw_data);
   endfunction
 
   virtual function void write64(bit [bus_params_pkg::BUS_AW-1:0] addr, logic [63:0] data);

hw/dv/sv/mem_bkdr_util/mem_bkdr_util_row_adapter.sv

@@ -0,0 +1,32 @@
+// Copyright lowRISC contributors (OpenTitan project).
+// Licensed under the Apache License, Version 2.0, see LICENSE for details.
+// SPDX-License-Identifier: Apache-2.0
+
+// Provide an abstract way to access the memory rows
+//
+// Integrators can subclass this to privide a specfic way of accessing a memory row
+// and incorporate the phyical architecture.
+//
+class mem_bkdr_util_row_adapter;
+  // Translates a raw read UVM data raw from the memory in a contigious
+  // row of memory.
+  //
+  virtual function uvm_hdl_data_t read_row(uvm_hdl_data_t read_data);
+    return read_data;
+  endfunction
+
+  // Translates a contigious UVM data row to the internal organzation of a row
+  // that can be written to the memory.
+  //
+  virtual function uvm_hdl_data_t write_row(uvm_hdl_data_t write_data);
+    return write_data;
+  endfunction
+
+  // Writes a 39 bit word into the row data depending on the memory architecture
+  virtual function uvm_hdl_data_t access_row_data39(bit [bus_params_pkg::BUS_AW-1:0] addr,
+                                                    logic [38:0] data,
+                                                    uvm_hdl_data_t row_data);
+    row_data[38:0] = data;
+    return row_data;
+  endfunction
+endclass