Semiconductor memory devices and methods for writing data in memory cells are provided. An exemplary method for writing data in a memory cell includes providing the memory cell with a first pull-up transistor, a first power supply line coupled to the first pull-up transistor, a second pull-up transistor, and a second power supply line coupled to the second pull-up transistor. The method further includes applying a primary voltage from the first power supply line to the first pull-up transistor. The method also includes applying a secondary voltage from the second power supply line to the second pull-up transistor, wherein the secondary voltage is higher than the primary voltage. Further, the method includes performing a write operation to save a selected value in the memory cell.