Apparatus and operation method of flash memory

A method of operating a flash memory device, the method comprising:

• (a) precharging, by a controller included in the device, a bitline and a wordline connected to a target memory cell according to an input of a first command;
• (b) performing, by the target memory cell, a first operation corresponding to the first command;
• (c) floating the bitline and the wordline for a threshold time after performing the first operation;
• and
• (d) determining whether a second command is input within the threshold time after performing the first operation, and controlling whether to recharge or discharge the bitline and the wordline according to an input timing of the second command,
• wherein step (d) comprises:
• recharging the bitline and the wordline connected to the target memory cell on which the second command is to be performed when the second command is input within the threshold time;
• and
• discharging the bitline and the wordline connected to the target memory cell on which the second command is to be performed when the second command is input after the threshold time has elapsed.

A flash memory device comprising:

• a plurality of memory cells;
• a memory cell array in which the plurality of memory cells are arranged;
• and
• a controller configured to control the plurality of memory cells,
• wherein the controller is configured to:
• precharge a bitline and a wordline connected to the memory cell according to an input of an ISPP (Incremental Step Pulse Programming) command, and cause a target memory cell to perform a first program operation according to a first program voltage;
• after performing the first program operation, discharge a wordline of the target memory cell only to a read voltage level, and perform a verification read operation while maintaining pass voltages in wordlines of remaining memory cells;
• recharge the wordline voltage of the target memory cell to a second program voltage and perform a second program operation while maintaining pass voltages in remaining wordlines;
• and
• after performing the second program operation, discharge the wordline of the target memory cell only to the read voltage level, and perform a verification read operation while maintaining pass voltages in the wordlines of remaining memory cells.

A method of operating a flash memory device, the method comprising:

• (a) precharging a bitline and a wordline connected to a memory cell according to an input of an ISPP (Incremental Step Pulse Programming) command, and performing a first program operation for a target memory cell according to a first program voltage;
• (b) after performing the first program operation, discharging a wordline of the target memory cell only to a read voltage level, and performing a verification read operation while maintaining pass voltages in wordlines of remaining memory cells;
• (c) recharging the wordline voltage of the target memory cell to a second program voltage, and performing a second program operation while maintaining pass voltages in remaining wordlines;
• and
• (d) after performing the second program operation, discharging the wordline of the target memory cell only to the read voltage level, and performing a verification read operation while maintaining pass voltages in wordlines of remaining memory cells.