Semiconductor memory device and operating method thereof

An operating method of a semiconductor memory device, comprising:

• inputting a program command for a selected memory block among a plurality of memory blocks;
• checking a program state of the selected memory block according to program mode information for the selected memory block stored in a Content-Addressable Memory (CAM) block among the plurality of memory blocks;
• selecting between a first program method, which programs data on an erased memory block, and a second program method, which programs data on a programmed memory block, depending on program mode information for the selected memory block;
• and
• performing a program operation on the selected memory block by the first program method if the selected memory block is a memory block that has only erased memory cells, and performing the program operation for the selected memory block by the second program method if the selected memory block is a memory block that has both the erased memory cells and programmed memory cells.

An operating method of a semiconductor memory device, comprising:

• inputting a read command for a selected memory block among a plurality of memory blocks;
• checking a program state of the selected memory block according to program mode information for the selected memory block stored in a Content-Addressable Memory (CAM) block among the plurality of memory blocks;
• selecting between a first read method and a second read method depending on program mode information for the selected memory block;
• and
• performing a read operation on the selected memory block by a first read method if the selected memory block is a memory block programmed by a first program method, which programs data on an erased memory block, and performing the read operation on the selected memory block by the second read method if the selected memory block is a memory block programmed by a second program method, which programs data on a programmed memory block.