INTEGER northCommMode
northCommMode = _tileCommModeN(bi,bj)
IF ( northCommMode .EQ. COMM_MSG ) THEN
ELSEIF ( northCommMode .EQ. COMM_PUT ) THEN
ELSEIF ( northCommMode .NE. COMM_NONE ) THEN
IF ( northCommMode .EQ. COMM_PUT ) southRecvAck(1,biN,bjN) = 1
IF ( northCommMode .EQ. COMM_GET ) southRecvAck(1,biN,bjN) = 1