 a sense amplifier for comparing a resistance in the MTJ cell in said first bit sub cell with a resistance in {HEAD ~ the MTJ cell} in said {TAIL ~ second bit sub cell} 
a sense amplifier for comparing a resistance in the MTJ cell in said first bit sub cell with a resistance in { HEAD ~ the MTJ cell } in said { TAIL ~ second bit sub cell }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL