diff --git a/src/Core.bsv b/src/Core.bsv
index 46a244e..3a39623 100644
--- a/src/Core.bsv
+++ b/src/Core.bsv
@@ -21,12 +21,13 @@ module mkCore(Core#(clkFreq));
     Real val = fromInteger(clkFreqInt);
     messageM("mkCore clkFreq" + realToString(val));
 
-    rule second_counter;
+    Bool pulse_every_second = counter == clkFreqUInt;
+
+    rule count;
         counter <= (counter == clkFreqUInt) ? 0 : counter + 1;
-        tick_second <= True;
     endrule
 
-    rule update_led(tick_second);
+    rule counting_led(pulse_every_second);
         led_out <= led_out + 1;
     endrule
 
@@ -37,7 +38,9 @@ module mkCore(Core#(clkFreq));
 		return led_out;
 	endmethod
     method Action put_char(Bit#(8) byte_in);
-		uart_out <= byte_in;
+        Bit#(8) value = byte_in;
+		uart_out <= value;
+        // led_out <= value;
 	endmethod
 endmodule
 
diff --git a/src/Deserializer.bsv b/src/Deserializer.bsv
index a60d6e8..6e9c0b6 100644
--- a/src/Deserializer.bsv
+++ b/src/Deserializer.bsv
@@ -41,6 +41,8 @@ module mkDeserialize#(Handle fileHandle)(IDeserializer#(clkFreq, baudRate));
         shiftReg <= {ftdiRxIn, shiftReg[7:1]};
     endrule
 
+    // an invariant enforced here is we can't call this method
+    // until shift reg is valid
     method Bit#(8) get() if (ftdiState == STOP && clkDivider.isAdvancing());
         return shiftReg;
     endmethod
diff --git a/src/Top.bsv b/src/Top.bsv
index 99f21ae..4b14ff4 100644
--- a/src/Top.bsv
+++ b/src/Top.bsv
@@ -43,15 +43,17 @@ module mkTop(ITop);
    messageM("Hallo!!" + realToString(5));
 
 	// connect up core device
-    rule core_led_o;
-		persist_led <= core.get_led;
-    endrule
-    rule core_char_device_o;
-		serializer.putBit8(core.get_char);
-    endrule
-    rule core_char_device_i;
-		core.put_char(deserializer.get);
-    endrule
+  rule core_led_o;
+    persist_led <= core.get_led;
+  endrule
+
+  rule core_char_device_o;
+    serializer.putBit8(core.get_char);
+  endrule
+
+  rule core_char_device_i;
+    core.put_char(deserializer.get);
+  endrule
 
 	// output methods
 	method Bit#(1) ftdi_rxd;