Mask programmable read-only memory (ROM) cell

摘要

A multi-bit programmable memory cell is provided that includes an access transistor and a plurality of N anti-fuse elements. The access transistor has a source coupled to a source line and a gate coupled to a word line. Each of the anti-fuse elements has a first terminal coupled to a drain of the access transistor, and a second terminal coupled to a corresponding bit line. At most, only one of the anti-fuse elements is programmed. The memory cell is capable of storing M bits, wherein N=2<M>-1. A method is provided for both programming and reading the memory cell. In another embodiment, the anti-fuse elements can be replaced with mask-programmable elements.