摘要:
Methods and systems are disclosed for code protection in non-volatile memory (NVM) systems. Information stored within NVM memory sectors, such as boot code or other code blocks, is protected using lockout codes and lockout keys written in program-once memory areas within the NVM systems. Further, lockout codes can be combined into a merged lockout code that can be stored in a merged protection register. The merged protection register is used to control write access to protected memory sectors. Lockout code/key pairs are written to the program-once area when a memory sector is protected. The program-once area, which stores the lockout code/key pairs, is not readable by external users. Once protected, a memory sector can not be updated without the lockout code/key pair.
摘要:
The present disclosure provides methods and circuits for managing failing sectors in a non-volatile memory. A record address and a read control signal are received, where the record address identifies a location in the non-volatile memory. The record address is compared with a plurality of dead sector addresses, where the dead sector addresses correspond to a subset of sectors located in the non-volatile memory. Data located at the record address is determined to be invalid in response to a combination of a first detection that the record address matches one of the dead sector addresses and a second detection that the read control signal indicates a read operation is requested to be performed on the non-volatile memory.
摘要:
A semiconductor memory device comprises a volatile memory and a non-volatile memory including a plurality of sectors. Each of the plurality of sectors configured to store a sector status indicator and a plurality of data records. A control module is coupled to the non-volatile memory and the volatile memory. The control module manages the sectors by scanning the sectors to identify the records with invalid data; changing the status indicator of a particular sector when all of the records in the particular sector are invalid, and discontinuing scanning the particular sector while all of the records in the particular sector are invalid.
摘要:
A method of transferring data from a non-volatile memory (NVM) having a plurality of blocks of an emulated electrically erasable (EEE) memory to a random access memory (RAM) of the EEE includes accessing a plurality of records, a record from each block. A determination is made if any of the data signals of the first data signals are valid and thereby considered valid data signals. If there is only one or none that are valid, the valid data, if any is loaded into RAM and the process continues with subsequent simultaneous accesses. If more than one is valid, then the processes is halted until the RAM is loaded with the valid data, then the method continues with subsequent simultaneous accesses of records.
摘要:
A method of transferring data from a non-volatile memory (NVM) having a plurality of blocks of an emulated electrically erasable (EEE) memory to a random access memory (RAM) of the EEE includes accessing a plurality of records, a record from each block. A determination is made if any of the data signals of the first data signals are valid and thereby considered valid data signals. If there is only one or none that are valid, the valid data, if any is loaded into RAM and the process continues with subsequent simultaneous accesses. If more than one is valid, then the processes is halted until the RAM is loaded with the valid data, then the method continues with subsequent simultaneous accesses of records.
摘要:
Methods and systems are disclosed for code protection in non-volatile memory (NVM) systems. Information stored within NVM memory sectors, such as boot code or other code blocks, is protected using lockout codes and lockout keys written in program-once memory areas within the NVM systems. Further, lockout codes can be combined into a merged lockout code that can be stored in a merged protection register. The merged protection register is used to control write access to protected memory sectors. Lockout code/key pairs are written to the program-once area when a memory sector is protected. The program-once area, which stores the lockout code/key pairs, is not readable by external users. Once protected, a memory sector can not be updated without the lockout code/key pair.
摘要:
Methods and systems are disclosed for digital control for regulation of program voltages for non-volatile memory (NVM) systems. The disclosed embodiments dynamically adjust program voltages based upon parameters associated with the cells to be programmed in order to account for IR (current-resistance) voltage drops that occur within program voltage distribution lines. Other voltage variations can also be accounted for with these dynamic adjustments, as well. The parameters for cells to be programmed can include, for example, cell address locations for the cells to be programmed, the number of cells to be programmed, and/or other desired parameters associated with the cells to be programmed. The disclosed embodiments use digital control values obtained from lookup tables based upon the cell parameters to adjust output voltages generated by voltage generation circuit blocks used to program the selected cells thereby tuning the program output voltage level to a predetermined desired level.
摘要:
A semiconductor memory device includes a non-volatile memory, a memory controller, and a charge pump system. The memory controller establishes first parameters for a first programming cycle of a first plurality of memory cells of the non-volatile memory prior to the first programming cycle being performed. The charge pump system includes a plurality of charge pumps and provides a first programming pulse for use in performing the first program cycle. The first programming pulse is provided by selecting, according to the first parameters, which of the plurality of charge pumps are to be enabled during the first program cycle and which are to be disabled during the first program cycle.
摘要:
Methods and systems are disclosed for symmetrical replication of data within multiple data subsystems for failure management in non-volatile memory (NVM) systems. Disclosed embodiments perform symmetrical write operations to multiple different data block subsystems so that duplicate subsystems are created. As the subsystems are operated symmetrically, address locations and pointers are the same for each subsystem. If an error is detected in data within one subsystem, the duplicated data at the same symmetrical location within a duplicate subsystem can be used. As such, the endurance and lifetime of NVM systems is greatly enhanced. These extended lifetime NVM systems can then be used, for example, to emulate EEPROM (erasable programmable read only memory) systems.
摘要:
Adaptive error correction for non-volatile memories is disclosed that dynamically adjusts sense amplifier read detection windows. Memory control circuitry uses error correction code (ECC) routines to detect bit errors that are non-correctable using these ECC routines. The memory control circuitry then dynamically adjusts sense amplifier read detection windows to allow for correct data to be determined. Corrected data can then be output to external circuitry. The corrected data can also be stored for later access when subsequent read operations attempt to access address locations that previously suffered bit failures. The adaptive error correction can also be used with respect to memories that are not non-volatile memories.