diff --git a/test/common/_test/__init__.py b/test/common/_test/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/test/common/_test/test_infrastructure.py b/test/common/_test/test_infrastructure.py
new file mode 100644
index 000000000..ecf1c84d9
--- /dev/null
+++ b/test/common/_test/test_infrastructure.py
@@ -0,0 +1,31 @@
+from amaranth import *
+from test.common import *
+
+
+class EmptyCircuit(Elaboratable):
+    def __init__(self):
+        pass
+
+    def elaborate(self, platform):
+        m = Module()
+        return m
+
+
+class TestNow(TestCaseWithSimulator):
+    def setUp(self):
+        self.test_cycles = 10
+        self.m = SimpleTestCircuit(EmptyCircuit())
+
+    def process(self):
+        for k in range(self.test_cycles):
+            now = yield Now()
+            assert k == now
+            # check if second call don't change the returned value
+            now = yield Now()
+            assert k == now
+
+            yield
+
+    def test_random(self):
+        with self.run_simulation(self.m, 50) as sim:
+            sim.add_sync_process(self.process)
diff --git a/test/common/functions.py b/test/common/functions.py
index 42b43cdf1..eb7abf886 100644
--- a/test/common/functions.py
+++ b/test/common/functions.py
@@ -1,11 +1,16 @@
 from amaranth import *
 from amaranth.hdl.ast import Statement
 from amaranth.sim.core import Command
-from typing import TypeVar, Any, Generator, TypeAlias
+from typing import TypeVar, Any, Generator, TypeAlias, TYPE_CHECKING, Union
 from transactron.utils._typing import RecordValueDict, RecordIntDict
 
+
+if TYPE_CHECKING:
+    from .infrastructure import CoreblocksCommand
+
+
 T = TypeVar("T")
-TestGen: TypeAlias = Generator[Command | Value | Statement | None, Any, T]
+TestGen: TypeAlias = Generator[Union[Command, Value, Statement, "CoreblocksCommand", None], Any, T]
 
 
 def set_inputs(values: RecordValueDict, field: Record) -> TestGen[None]:
diff --git a/test/common/infrastructure.py b/test/common/infrastructure.py
index e1141a0eb..058d5b9ed 100644
--- a/test/common/infrastructure.py
+++ b/test/common/infrastructure.py
@@ -3,10 +3,12 @@
 import unittest
 import functools
 from contextlib import contextmanager, nullcontext
-from typing import TypeVar, Generic, Type, TypeGuard, Any, Union, Callable, cast
+from typing import TypeVar, Generic, Type, TypeGuard, Any, Union, Callable, cast, TypeAlias
+from abc import ABC
 from amaranth import *
 from amaranth.sim import *
 from .testbenchio import TestbenchIO
+from .functions import TestGen
 from ..gtkw_extension import write_vcd_ext
 from transactron import Method
 from transactron.lib import AdapterTrans
@@ -14,7 +16,7 @@
 from transactron.utils import ModuleConnector, HasElaborate, auto_debug_signals, HasDebugSignals
 
 T = TypeVar("T")
-_T_nested_collection = T | list["_T_nested_collection[T]"] | dict[str, "_T_nested_collection[T]"]
+_T_nested_collection: TypeAlias = T | list["_T_nested_collection[T]"] | dict[str, "_T_nested_collection[T]"]
 
 
 def guard_nested_collection(cont: Any, t: Type[T]) -> TypeGuard[_T_nested_collection[T]]:
@@ -99,6 +101,40 @@ def elaborate(self, platform) -> HasElaborate:
         return m
 
 
+class CoreblocksCommand(ABC):
+    pass
+
+
+class Now(CoreblocksCommand):
+    pass
+
+
+class SyncProcessWrapper:
+    def __init__(self, f):
+        self.org_process = f
+        self.current_cycle = 0
+
+    def _wrapping_function(self):
+        response = None
+        org_coroutine = self.org_process()
+        try:
+            while True:
+                # call orginal test process and catch data yielded by it in `command` variable
+                command = org_coroutine.send(response)
+                # If process wait for new cycle
+                if command is None:
+                    self.current_cycle += 1
+                    # forward to amaranth
+                    yield
+                elif isinstance(command, Now):
+                    response = self.current_cycle
+                # Pass everything else to amaranth simulator without modifications
+                else:
+                    response = yield command
+        except StopIteration:
+            pass
+
+
 class PysimSimulator(Simulator):
     def __init__(self, module: HasElaborate, max_cycles: float = 10e4, add_transaction_module=True, traces_file=None):
         test_module = TestModule(module, add_transaction_module)
@@ -133,6 +169,10 @@ def __init__(self, module: HasElaborate, max_cycles: float = 10e4, add_transacti
 
         self.deadline = clk_period * max_cycles
 
+    def add_sync_process(self, f: Callable[[], TestGen]):
+        f_wrapped = SyncProcessWrapper(f)
+        super().add_sync_process(f_wrapped._wrapping_function)
+
     def run(self) -> bool:
         with self.ctx:
             self.run_until(self.deadline)