Add nonexistent device test

Author: alexforencich

tb/test_i2c_master.py

@@ -399,6 +399,37 @@ def check():
 
         yield delay(100)
 
+        yield clk.posedge
+        print("test 5: write to nonexistent device")
+        current_test.next = 5
+
+        cmd_source.send([(
+            0x52, # address
+            0,    # start
+            0,    # read
+            0,    # write
+            1,    # write_multiple
+            1     # stop
+        )])
+        data_source.send((b'\x00\x04'+b'\xde\xad\xbe\xef'))
+
+        got_missed_ack = False
+
+        for k in range(1000):
+            got_missed_ack |= missed_ack
+            yield clk.posedge
+
+        assert got_missed_ack
+
+        yield clk.posedge
+        yield clk.posedge
+        yield clk.posedge
+        while busy or bus_active or not cmd_source.empty():
+            yield clk.posedge
+        yield clk.posedge
+
+        yield delay(100)
+
         raise StopSimulation
 
     return dut, cmd_source_logic, data_source_logic, data_sink_logic, i2c_mem_logic1, i2c_mem_logic2, bus, clkgen, check

tb/test_i2c_master_wbs_8.py

@@ -338,6 +338,35 @@ def check():
 
         yield delay(100)
 
+        yield clk.posedge
+        print("test 5: write to nonexistent device")
+        current_test.next = 5
+
+        wbm_inst.init_write(2, b'\x52\x04\x00')
+        wbm_inst.init_write(3, b'\x04\x04')
+        wbm_inst.init_write(3, b'\x04\xde')
+        wbm_inst.init_write(3, b'\x04\xad')
+        wbm_inst.init_write(3, b'\x04\xbe')
+        wbm_inst.init_write(3, b'\x14\xef')
+
+        yield wbm_inst.wait()
+        yield clk.posedge
+
+        got_missed_ack = False
+
+        while True:
+            wbm_inst.init_read(0, 1)
+            yield wbm_inst.wait()
+            data = wbm_inst.get_read_data()
+            if data[1][0] & 0x08:
+                got_missed_ack = True
+            if data[1][0] & 0x03 == 0:
+                break
+
+        assert got_missed_ack
+
+        yield delay(100)
+
         raise StopSimulation
 
     return dut, wbm_logic, i2c_mem_logic1, i2c_mem_logic2, bus, clkgen, check