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

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()