Diagnosis flow for read-only memories
AssigneeSTMicroelectronics International N.V.
InventorSuraj Prakash
Life of this patent
Estimating the term…
Abstract
A system and a method for diagnosis flow for a read-only memory (ROM) includes determining whether a window of the ROM is faulty, based on a pre-computed signature and a computed signature corresponding to the window. Based on the determination, the size of the window is reduced to form at least two reduced windows. It is further ascertained whether the at least two reduced windows are faulty based on pre-computed signatures corresponding to the at least two reduced windows and computed signatures corresponding to the at least two reduced windows.
Claims22
A system-on-a-chip (SOC) comprising:
- a memory;
- and
- a Built-in Self Test (BIST) unit coupled to the memory, the BIST unit configured to
- compute a signature based on contents from a window of the memory,
- receive a pre-computed signature associated with the contents from the window of the memory,
- compare the computed signature with the pre-computed signature, and
- determine whether a window reduction is required for the window of the memory, and if so,
- reduce the window of the memory into a plurality of reduced windows to identify at least one fault present in the memory based on the results of the comparison of the pre-computed signature and the computed signature,
- generate a plurality of reduced computed signatures from contents in the plurality of reduced windows of the memory, and
- compare a plurality of reduced pre-computed signatures with the plurality of reduced computed signatures.
A memory circuit comprising:
- a memory;
- and
- a processing unit coupled to the memory, the processing unit configured to
- compute a signature based on contents from a window of the memory, receive a pre-computed signature associated with the contents from the window of the memory,
- compare the computed signature with the pre-computed signature, and
- determine whether a window reduction is required for the window of the memory, and if so,
- reduce the window of the memory into a plurality of reduced windows to identify at least one fault present in the memory based on the results of the comparison of the pre-computed signature and the computed signature,
- generate a plurality of reduced computed signatures from contents in the plurality of reduced windows of the memory, and
- compare a plurality of reduced pre-computed signatures with the plurality of reduced computed signatures.
A method for identifying faults in a memory circuit comprising a memory, and a processing unit coupled to the memory, the method comprising:
- operating the processing unit to
- compute a signature based on contents from a window of the memory, receive a pre-computed signature associated with the contents from the window of the memory,
- compare the computed signature with the pre-computed signature, and
- determine whether a window reduction is required for the window of the memory, and if so,
- reduce the window of the memory into a plurality of reduced windows to identify at least one fault present in the memory based on the results of the comparison of the pre-computed signature and the computed signature,
- generate a plurality of reduced computed signatures from contents in the plurality of reduced windows of the memory, and
- compare a plurality of reduced pre-computed signatures with the plurality of reduced computed signatures.
Dependencies are inferred from the claim text.