0		 		{vlow}
+ {tbit-trf/2}  {vlow}

+ {trf}     	{vhigh}
+ {tbit-trf}    {vhigh}

+ {trf}     	{vlow}
+ {tbit-trf}    {vlow}

+ {trf}     	{vhigh}
+ {tbit-trf}    {vhigh}

+ {trf}     	{vlow}
+ {tbit-trf}    {vlow}

+ {trf}     	{vlow}
+ {tbit-trf}    {vlow}

+ {trf}     	{vhigh}
+ {tbit-trf}    {vhigh}

+ {trf}     	{vlow}
+ {tbit-trf}    {vlow}