US Patent 7548456 Combo memory cell

A combo memory cell having a SRAM cell and a mask-ROM code programmer. The SRAM cell comprises first and second inverters. The first inverter comprises a first PMOS transistor and a first NMOS transistor. Gates of the first PMOS and NMOS transistors are commonly connected to a first input node and drains thereof commonly connected to a first output node. The second inverter comprises a second PMOS transistor and a second NMOS transistor. Gates of the second PMOS and NMOS transistors are commonly connected to a second input node and drains thereof commonly connected to a second output node. The first input node and the second output node are connected, as are the second input node and the first output node. The mask-ROM code programmer is coupled to the sources of the first and second PMOS transistors or the first and second NMOS transistors.