Abstract: The disclosure is a NAND flash memory including a data loading circuit providing a program data bit into a page buffer having first and second latches. During a data loading operation for programming, the data loading circuit puts a pass data bit into a page buffer corresponding to a defective column, instead of a program data bit that is assigned to the defective column, responding to information of a column address involved in the defective column. It is available to provide a pass/fail check circuit for program-verifying without employing a fuse arrangement, making data of the defective column not affect a program-verifying result.

Abstract: A column select line enable circuit prevents the first bit in a sequence of output data from being missed, thereby reducing tRCD in a synchronous memory device. The circuit delays a predetermined period of time after a row active command is applied to the memory device and then activates a column select enable line regardless of the state of the system clock signal. The column select enable line is maintained in an active state for a second period of time to allow the first bit of data to be read from the device. Thereafter, the column select enable line is enabled and disabled responsive to the system clock signal to read the remaining bits in the sequence of output data in a conventional manner. In a preferred embodiment, the circuit does not enable the column select enable line unless a decoded bank address signal is active.