{HEAD ~ a second switch} that is provided between {TAIL ~ the second constant current source} and the first bit line, the second switch being formed by a MONOS type transistor 
is provided between
{ HEAD ~ a second switch } that is provided between { TAIL ~ the second constant current source } and the first bit line , the second switch being formed by a MONOS type transistor
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH