Abstract: A flash memory that could not have completed an operation within a time required by a host may be able to work with the host by dividing the operation into phases that may be completed within the allocated time. As a result, a type of memory that would otherwise be unable to be implemented in a format, such as a memory card, may be used effectively.

Abstract: A flash memory that could not have completed an operation within a time required by a host may be able to work with the host by dividing the operation into phases that may be completed within the allocated time. As a result, a type of memory that would otherwise be unable to be implemented in a format, such as a memory card, may be used effectively.

Abstract: In some embodiments, an apparatus and methods for storing data which self-compensate for erase performance degradation. Such an apparatus includes, in an exemplary embodiment, a plurality of memory blocks individually erasable during erase cycles by the application of erase pulses thereto having appropriate erase pulse voltage levels, and a memory location uniquely associated with each memory block that stores an initial erase pulse voltage level therefor to be used during an erase cycle. Such methods include, in an exemplary embodiment, counting the number of erase pulses applied to each memory block during an erase cycle therefor, comparing the count for each memory block to a threshold count value, and updating the stored initial erase pulse voltage level to be used during a subsequent erase cycle for each respective memory block if the count for that memory block is not less than the threshold count. Other embodiments are described and claimed.

Abstract: Systems including a bit sequence program controller to program in sequence non-volatile memory cells in an array of programmable non-volatile memory cells. The bit sequence program controller determines the bits that require programming by comparing the bits of the program word with an erased logical state of the array of programmable non-volatile memory cells. The bit sequence program controller further indicates which non-volatile memory cells in a word of non-volatile memory cells in the array of non-volatile memory cells require programming to match the program word. The bit sequence program controller counts the number of the bits that require programming in the program word by counting the number of bits of the program word that are not in an erased logical state to determine when the programming should be completed.

Abstract: Systems including a bit sequence program controller to program in sequence non-volatile memory cells in an array of programmable non-volatile memory cells. The bit sequence program controller determines the bits that require programming by comparing the bits of the program word with an erased logical state of the array of programmable non-volatile memory cells. The bit sequence program controller further indicates which nonvolatile memory cells in a word of non-volatile memory cells in the array of non-volatile memory cells require programming to match the program word. The bit sequence program controller counts the number of the bits that require programming in the program word by counting the number of bits of the program word that are not in an erased logical state to determine when the programming should be completed.

Abstract: A bit sequence program controller to program in sequence non-volatile memory cells in an array of programmable non-volatile memory cells. The bit sequence program controller determines the bits that require programming by comparing the bits of the program word with an erased logical state of the array of programmable non-volatile memory cells. The bit sequence program controller further indicates which non-volatile memory cells in a word of non-volatile memory cells in the array of non-volatile memory cells require programming to match the program word. The bit sequence program controller counts the number of the bits that require programming in the program word by counting the number of bits of the program word that are not in an erased logical state to determine when the programming should be completed.

Abstract: A method and apparatus suspend a program operation in a nonvolatile writeable memory. The nonvolatile writeable memory includes a memory array, a command register and memory array control circuitry. The command register decodes a program suspend command and provides a suspend signal as an output. The memory array control circuitry is coupled to receive the suspend signal from the command register. The memory array control circuitry performs a program operation in which data is written to the memory array. The memory array control circuitry suspends the program operation upon receiving the suspend signal.

Abstract: A flash memory device including a first memory array, block locking circuitry, and control circuitry. The memory array includes a plurality of memory blocks each having a memory cell. The block locking circuitry includes a plurality of block lock-bits and a master lock-bit. Each block lock-bit corresponds to one of the plurality of memory blocks and indicates whether the corresponding memory block is locked. The master lock-bit indicates whether the plurality of block lock-bits are locked. The control circuitry is configured to receive a passcode that causes the control circuitry to override the master lock-bit. The control circuitry may also be configured to receive a passcode that causes the control circuitry to override one of the block lock-bits.

Abstract: A flash memory device including a first memory array, a control circuit coupled to the first memory array, and a second independent memory array coupled to the control circuit. The first memory array includes a plurality of memory blocks each having a memory cell. The memory cell may be a nonvolatile flash memory cell. The control circuit controls the programming, erasing, and reading of the memory cells. The second memory array includes a plurality of block lock-bits each corresponding to one of the plurality of memory blocks. The state of each block lock-bit indicates whether the memory cell in the corresponding memory block is locked. The second memory array may also include a master lock-bit that indicates whether the block lock-bits are locked.

Abstract: A method of writing to flash memory cells in a flash memory device. The flash memory device includes a first memory array and a second independent memory array. The first memory array includes memory blocks each having a memory cell. The second independent memory array includes block lock-bits each corresponding to one of the memory blocks. The method of writing to a memory cell in one of the memory blocks of the first memory array includes the steps of issuing a command to write to the memory cell, determining if a corresponding block lock-bit in the second independent memory array is set, and writing to the memory cell if the corresponding block lock-bit is not set.

Abstract: A method and apparatus suspend a program operation in a nonvolatile writeable memory. The nonvolatile writeable memory includes a memory array, a command register, and memory array control circuitry. The command register decodes a program suspend command and provides a suspend signal as an output. The memory array control circuitry is coupled to receive the suspend signal from the command register. The memory array control circuitry performs a program operation in which data is written to the memory array. The memory array control circuitry suspends the program operation upon receiving the suspend signal.

Abstract: Circuitry for propagating test mode signals associated with a memory array including a plurality of circuits for storing test mode signals, apparatus for selectively providing test mode data to each of the circuits for storing test mode signals, and apparatus for simultaneously activating all of the circuits for storing test mode signals to provide output signals to be used for testing.

Abstract: A method of enabling access to a test mode of a semiconductor memory in response to user commands. The method enables test mode access only when a number of "keys" are presented in the proper sequence via the memory device pins. During the first phase of the unlocking process, an array controller determines whether the correct confirmation codes were input via the address and data pins. If they were, the array controller proceeds to the second phase of the unlocking process. During the second phase voltage levels on selected control pins are checked for a transition to a first voltage level. If the control pins transition as required, the array controller proceeds to the third phase. During the third phase, the array controller waits a limited time for receipt of a second test mode enable command. The second test mode enable command must be followed by correct confirmation codes. If the third phase is successfully completed, the array controller writes to a test mode enable access register.

Abstract: A circuit for providing a read only value for an integrated circuit which integrated circuit includes a plurality of layers of material any one of which may be changed if the integrated circuit is revised comprising a pair of conductors positioned closely adjacent one another in each of the layers of material which carries conductors, a first source of voltage connected to one of the conductors on one of the layers for providing a first binary value, a second source of voltage connected to another of the conductors on one of the layers for providing a second binary value, an output terminal on one of the layers, and apparatus for connecting a selected one of the sources to the output terminal through one of the conductors on each of the layers.

Abstract: A method of determining erasure characteristics of a nonvolatile semiconductor memory array using an on-board write state machine is described. The method begins by configuring the write state machine to apply a single erase pulse to the array and then issuing an erase command. If array erasure is unsuccessful, another erase command is issued. Erase commands are reissued until every address within the array is successfully erased.

Abstract: An apparatus for testing a unit comprising an internal processor coupled to a register by an internal bus. The internal processor is programmed so that it can execute an algorithm. When executed, the algorithm performs an operation on the unit. The register is for storing a state datum. The internal bus is used by the internal processor to access the state datum when the internal processor is executing the algorithm. The testing apparatus comprises an external processor disposed external to the unit and an interface and switch disposed on the unit. The interface is coupled to the internal and external processors and is for receiving a plurality of commands from the external processor. The commands include an internal processor command and an open trap command. If issued, the internal processor command causes the internal processor to execute the algorithm. The switch is coupled to the interface and coupled between the internal processor and the internal bus.

Abstract: A method is described for verifying the operation of next state logic within a write state machine for automatically programming and erasing a flash memory. Verification of the next state logic's operation begins by configuring the write state machine in a test mode. Afterward, the next state logic is cycled through its possible output states by providing the next state logic with all possible input states. Outputs from next state logic are compared to expected outputs, thereby verifying the operation of the next state logic. Also described is circuitry for verifying the operation of next state logic within a write state machine. The circuitry includes test registers for storing test signals. In response to the test signals a first means isolates the next state logic from the write state machine. A second means provides alternative inputs to the next state logic in response to the test signals.

Abstract: An arrangement for generating signals for generating a particular set of test conditions within a digital circuit including a plurality of latches for storing individual bits of data representing individual operations to be accomplished within the digital circuitry, the latches each having input and output terminals; the output terminals of each of the latches being connected to individual portions of the digital circuitry to effect an individual operation thereby; apparatus connected to the input terminals of the latches for setting individual selected ones of the latches to provide selected test conditions; and apparatus for transferring the condition of a selected number of the latches simultaneously to effect a selected test condition.

Abstract: A semiconductor flash EPROM/EEPROM device which includes a command port controller for receiving command instructions from a data bus coupled to the memory device. Instruction words to a command port controller operates to instruct the device to perform read, erase, program, or verify functions and the command port controller generates necessary control signals to cause the memory to function appropriately. By utilizing the command port controller the memory device can be erased and programmed while the device is in the circuit and permits pin compatibility with the prior art EPROM and EEPROMs.

Abstract: A flash memory device including a first memory array, a control circuit coupled to the first memory array, and a second independent memory array coupled to the control circuit. The first memory array includes a plurality of memory blocks each having a memory cell. The memory cell may be a nonvolatile flash memory cell. The control circuit controls the programming, erasing, and reading of the memory cells. The second memory array includes a plurality of block lock-bits each corresponding to one of the plurality of memory blocks. The state of each block lock-bit indicates whether the memory cell in the corresponding memory block is locked. The second memory array may also include a master lock-bit that indicates whether the block lock-bits are locked.