Abstract: A method of operating a semiconductor device having a plurality of memory cells programmable to a plurality of program states, wherein each of the program states is associated with a range of read currents bounded by a pair of reference read currents, comprising storing data by programming a first memory cell of the plurality of memory cells to a first program state of the plurality of program states, and programming a second memory cell of the plurality of memory cells to a second program state of the plurality of program states; and reading the data by reading the first memory cell to determine a first read current through the first memory cell, reading the second memory cell to determine a second read current through the second memory cell, and comparing the first read current, the second read current and a first one of the reference read currents to each other.

Abstract: In one example, a method comprises storing (n-1) partitions of a first image of code in a first set of banks in single-level cell format, wherein the first set of banks comprise (n-1) of n banks of flash memory cells; and storing (n-1) partitions of the first image and (n-1) partitions of a second image of code in a second set of banks in multi-level cell format, wherein the second set of banks comprise (n-1) of the n banks and the second set of banks comprises a bank not contained in the first set of banks.

Abstract: A method of testing non-volatile memory cells formed on a die includes erasing the memory cells and performing a first read operation to determine a lowest read current RC1 for the memory cells and a first number N1 of the memory cells having the lowest read current RC1. A second read operation is performed to determine a second number N2 of the memory cells having a read current not exceeding a target read current RC2. The target read current RC2 is equal to the lowest read current RC1 plus a predetermined current value. The die is determined to be acceptable if the second number N2 is determined to exceed the first number N1 plus a predetermined number. The die is determined to be defective if the second number N2 is determined not to exceed the first number N1 plus the predetermined number.

Abstract: A method of testing non-volatile memory cells formed on a die includes erasing the memory cells and performing a first read operation to determine a lowest read current RC1 for the memory cells and a first number N1 of the memory cells having the lowest read current RC1. A second read operation is performed to determine a second number N2 of the memory cells having a read current not exceeding a target read current RC2. The target read current RC2 is equal to the lowest read current RC1 plus a predetermined current value. The die is determined to be acceptable if the second number N2 is determined to exceed the first number N1 plus a predetermined number. The die is determined to be defective if the second number N2 is determined not to exceed the first number N1 plus the predetermined number.