Refactor readback mux implementation. Improves performance (#155) and eliminates illegal streaming operator usage (#165)

tests/test_only_external_blocks/regblock.rdl

@@ -0,0 +1,11 @@
+addrmap top {
+    mem ext_mem #(
+        longint SIZE = 0x100
+    ) {
+        memwidth = 32;
+        mementries = SIZE / 4;
+    };
+
+    external ext_mem #(.SIZE(0x10))  mem1 @ 0x0000;
+    external ext_mem #(.SIZE(0x90))  mem2 @ 0x0200;
+};

tests/test_only_external_blocks/tb_template.sv

@@ -0,0 +1,115 @@
+{% extends "lib/tb_base.sv" %}
+
+
+
+{%- block dut_support %}
+    {% sv_line_anchor %}
+
+    external_block #(
+        .ADDR_WIDTH($clog2('h10))
+    ) mem1_inst (
+        .clk(clk),
+        .rst(rst),
+
+        .req(hwif_out.mem1.req),
+        .req_is_wr(hwif_out.mem1.req_is_wr),
+        .addr(hwif_out.mem1.addr),
+        .wr_data(hwif_out.mem1.wr_data),
+        .wr_biten(hwif_out.mem1.wr_biten),
+        .rd_ack(hwif_in.mem1.rd_ack),
+        .rd_data(hwif_in.mem1.rd_data),
+        .wr_ack(hwif_in.mem1.wr_ack)
+    );
+
+    external_block #(
+        .ADDR_WIDTH($clog2('h90))
+    ) mem2_inst (
+        .clk(clk),
+        .rst(rst),
+
+        .req(hwif_out.mem2.req),
+        .req_is_wr(hwif_out.mem2.req_is_wr),
+        .addr(hwif_out.mem2.addr),
+        .wr_data(hwif_out.mem2.wr_data),
+        .wr_biten(hwif_out.mem2.wr_biten),
+        .rd_ack(hwif_in.mem2.rd_ack),
+        .rd_data(hwif_in.mem2.rd_data),
+        .wr_ack(hwif_in.mem2.wr_ack)
+    );
+
+{%- endblock %}
+
+
+
+{% block seq %}
+    {% sv_line_anchor %}
+    ##1;
+    cb.rst <= '0;
+    ##1;
+
+    //--------------------------------------------------------------------------
+    // Simple read/write tests
+    //--------------------------------------------------------------------------
+    // mem1
+    repeat(32) begin
+        logic [31:0] x;
+        int unsigned addr;
+        x = $urandom();
+        addr = 'h0;
+        addr += $urandom_range(('h10 / 4) - 1) * 4;
+        cpuif.write(addr, x);
+        cpuif.assert_read(addr, x);
+    end
+
+    // mem2
+    repeat(32) begin
+        logic [31:0] x;
+        int unsigned addr;
+        x = $urandom();
+        addr = 'h200;
+        addr += $urandom_range(('h90 / 4) - 1) * 4;
+        cpuif.write(addr, x);
+        cpuif.assert_read(addr, x);
+    end
+
+    //--------------------------------------------------------------------------
+    // Pipelined access
+    //--------------------------------------------------------------------------
+    // init array with unique known value
+    for(int i=0; i<('h10 / 4); i++) begin
+        cpuif.write('h0 + i*4, 'h1000 + i);
+    end
+    for(int i=0; i<('h90 / 4); i++) begin
+        cpuif.write('h200 + i*4, 'h3000 + i);
+    end
+
+    // random pipelined read/writes
+    repeat(256) begin
+        fork
+            begin
+                int i;
+                logic [31:0] x;
+                int unsigned addr;
+                case($urandom_range(1))
+                    0: begin
+                        i = $urandom_range(('h10 / 4) - 1);
+                        x = 'h1000 + i;
+                        addr = 'h0 + i*4;
+                    end
+                    1: begin
+                        i = $urandom_range(('h90 / 4) - 1);
+                        x = 'h3000 + i;
+                        addr = 'h200 + i*4;
+                    end
+                endcase
+
+                case($urandom_range(1))
+                    0: cpuif.write(addr, x);
+                    1: cpuif.assert_read(addr, x);
+                endcase
+            end
+        join_none
+    end
+    wait fork;
+
+{% endblock %}

tests/test_only_external_blocks/testcase.py

@@ -0,0 +1,29 @@
+from parameterized import parameterized_class
+
+from ..lib.cpuifs.apb4 import APB4
+from ..lib.cpuifs.axi4lite import AXI4Lite
+from ..lib.cpuifs.passthrough import Passthrough
+from ..lib.sim_testcase import SimTestCase
+from ..lib.test_params import get_permutation_class_name, get_permutations
+
+
+@parameterized_class(get_permutations({
+    "cpuif": [
+        APB4(),
+        Passthrough(),
+    ],
+    "retime_read_fanin": [True, False],
+    "retime_read_response": [True, False],
+    "retime_external": [True, False],
+}), class_name_func=get_permutation_class_name)
+class Test(SimTestCase):
+    extra_tb_files = [
+        "../lib/external_reg.sv",
+        "../lib/external_block.sv",
+    ]
+    init_hwif_in = False
+    clocking_hwif_in = False
+    timeout_clk_cycles = 30000
+
+    def test_dut(self):
+        self.run_test()