Nonvolatile memory device including page buffer and method for verifying program operation thereof

A method of a program verify operation of a nonvolatile memory, the method comprising:

• storing first and second sensing data sensed from different memory cells in first and second page buffers according to a program verify operation, respectively;
• generating first verify data from the first sensing data in the first page buffer;
• transmitting the second sensing data from the second page buffer to the first page buffer;
• and
• generating second verify data in the first page buffer by accumulating the transmitted second sensing data and the first verify data.

A method, executed by a page buffer circuit of a nonvolatile memory device (NVM), of detecting errors within memory cells of the NVM read by the page buffer circuit during a single program verify operation, the method comprising:

• executing a first binary logic operation between:
• (1) a first data value sensed from a first memory cell by a first page buffer of the page buffer circuit during the program verify operation and (2) a second data value sensed from a second memory cell by a second page buffer of the page buffer circuit during the program verify operation;
• and
• determining the number of program errors existing among the first and second memory cells based upon the outcome of the first binary logic operation and the second data value.