摘要:
A method for detecting word line leakage in a memory device includes coupling a first plurality of word lines in the memory device to a voltage source while grounding a second plurality of word lines. Each of the second plurality of word lines is adjacent to a corresponding one of the first plurality of word lines. The method includes waiting for a period of time to allow the word lines to reach a predetermined read voltage level. The method also includes decoupling the first plurality of word lines from the voltage source and waiting for a second predetermined period of time to allow the first plurality of word lines to discharge. The method further includes sensing a current associated with the word lines, and comparing the current with a predetermined reference current which is selected for identifying a word line leakage condition associated with the first plurality of word lines.
摘要:
Methods and apparatuses are disclosed in which a repair instruction, such as from a tester, causes an integrated circuit undergoing testing to substitute defective locations of a first set of memory cells in the integrated circuit with a second set of memory cells in the integrated circuit, despite the repair instruction omitting the defective locations of the first set of memory cells of the integrated circuit.
摘要:
A reference current is generated by inputting an adjusting current, which is about two or three micro amperes larger than the drain current of the NROM cell having a highest threshold voltage of the flash memory, a reference current with an initial value, effectively the same as the drain current of the NROM cell with a lowest threshold voltage. The method involves sensing the difference between the reference current decreasing from its initial value, and the adjusting current under a predetermined memory speed.
摘要:
Some embodiments of the present invention provide a memory device including a first memory array having a first word line and a comparator circuit having a first terminal coupled to a reference voltage and a second terminal coupled to a first switch selectively coupling the first word line to a power source or the second terminal. In an embodiment, the reference voltage is selected for identifying a leakage condition associated with the first word line. In another embodiment, the first switch is configured to couple the first word line to the power source for a first predetermined period of time to allow charging of the first word line. In another embodiment, the first switch is configured to couple the first word line to the second terminal of the comparator for at least a second predetermined period of time.
摘要:
Methods and apparatuses are disclosed in which a repair instruction, such as from a tester, causes an integrated circuit undergoing testing to substitute defective locations of a first set of memory cells in the integrated circuit with a second set of memory cells in the integrated circuit, despite the repair instruction omitting the defective locations of the first set of memory cells of the integrated circuit.
摘要:
Some embodiments of the present invention provide a memory device including a first memory array having a first word line and a comparator circuit having a first terminal coupled to a reference voltage and a second terminal coupled to a first switch selectively coupling the first word line to a power source or the second terminal. In an embodiment, the reference voltage is selected for identifying a leakage condition associated with the first word line. In another embodiment, the first switch is configured to couple the first word line to the power source for a first predetermined period of time to allow charging of the first word line. In another embodiment, the first switch is configured to couple the first word line to the second terminal of the comparator for at least a second predetermined period of time.
摘要:
According to an embodiment of the present invention, a method for detecting word line leakage in a memory device includes coupling a first word line in the memory device to a voltage source while coupling a second word line in the memory device to a ground level voltage. Next, the first word line is decoupled from the voltage source. The method also includes comparing a current of the first word line with a predetermined reference current for determining a leakage condition of the word line.
摘要:
A method for detecting word line leakage in a memory device includes coupling a first plurality of word lines in the memory device to a voltage source while grounding a second plurality of word lines. Each of the second plurality of word lines is adjacent to a corresponding one of the first plurality of word lines. The method includes waiting for a period of time to allow the word lines to reach a predetermined read voltage level. The method also includes decoupling the first plurality of word lines from the voltage source and waiting for a second predetermined period of time to allow the first plurality of word lines to discharge. The method further includes sensing a current associated with the word lines, and comparing the current with a predetermined reference current which is selected for identifying a word line leakage condition associated with the first plurality of word lines.
摘要:
The present invention provides a dual reference cell sensing scheme for non-volatile memory. A high voltage reference cell and a low voltage reference cell are individually coupled to two sense amplifiers for providing two distinct reference voltages for comparison against the memory cell voltage. The output of the two sense amplifiers is further connected to a second stage sense amplifier to determine the status of the memory. The dual reference cell sensing scheme provides an increased sensing window which increases performance under low voltage application. The dual reference cell sensing scheme can be implemented by either voltage-based, current-based, or ground.
摘要:
A system for reading data in a memory cell includes three comparators, each of which has two inputs. A first reference cell having a low reference voltage is coupled to one input of the first comparator. A second reference cell having a high reference voltage is coupled to one input of the second comparator. A memory cell having a memory cell voltage is coupled to the other input of the first and second comparators. One input of the third comparator is coupled to the first comparator's output signal, which includes a difference voltage between the memory cell voltage and the low reference voltage. The other input of the third comparator is coupled to the second comparator's output signal, which includes a difference voltage between the memory cell voltage and the high reference voltage. A method and apparatus for reading data in a memory cell also are described.