Tri-level-cell dynamic random access memory (DRAM) stores 3 levels of voltage (0, VDD/2, VDD) into a plurality of memory cells. Selected memory cell connected to bitline (BLT) to develop signal voltage, and adjacent reference bitline (BLR) develops reference voltage at VDD/2. An asymmetrical sensing amplifier (ASA), which has alternative positive offset and negative offset, is used to sense signal voltage and reference voltage for both their difference and sameness. ASA control signals, A and B, switch at different timing points or at different voltage level or the combination of both to have offset voltage set at either positive or negative polarity. Two consecutive read out from one ASA or one single read out from two ASA can be implemented to read memory cells data to local IOs. Output from ASA will be used to restore voltage back to the accessed memory cells.