A 13.8% Speed-Enhanced 1T Mask ROM by Algorithmically Signed Program Data on 3-nm Fin-FET Logic CMOS

We have proposed an algorithmically signed mask ROM, where a sign column is attached to an original ROM bitcell array. By selecting appropriate sign bits for given data, ‘1’-bit ratio to be programed for each column can be constrained within a narrow range, which profoundly mitigates tradeoff between read access time and read margin. SPICE simulations and silicon measurement for a 1.8-Mbit signed ROM on 3-nm Fin-FET logic CMOS demonstrate improvement in read access time by 12.7% and 13.8%, respectively.