Abstract: Various embodiments of the invention may provide one or more non-volatile storage entities, such as a register or a storage array, to store configuration information for a memory device. The specified configuration may then be enabled at the occurrence of a specified event, such as power-up and/or reset.

Abstract: A low-power input buffer for a nonvolatile writeable memory is described. The low-power input buffer accepts input signals having one of a number of pairs of logic levels. The low-power input buffer provides output signals having a pair of logic levels that may differ from the logic levels of the input signal. The low-power input buffer comprises an inverter that receives an input signal, a circuit with a relatively low voltage drop, and a feedback pull-up device. The circuit with the relatively low voltage drop causes the low-power input buffer to accept input signals having one pair of logic levels while providing signals that may have a different pair of logic levels. The feedback pull-up device prevents the low-power input buffer from drawing leakage current. The low-power input buffer is coupled to the nonvolatile writeable memory and coupled to the same power supply output as the nonvolatile writeable memory.

Abstract: A read-while-write memory device. The read-while-write memory device includes a read memory plane and a write memory plane. A first number of read sense amplifiers greater than one is coupled in parallel to the read memory plane in response to a memory read operation. A second number of verify sense amplifiers greater than zero and less than the first number is coupled to the write memory plane in response to one of a memory write or erase operation.

Abstract: A method and apparatus for controlling use of an electronic system is described. Use of the electronic system is controlled by programming at least one unique code into an auxiliary memory of the electronic system. The auxiliary memory is a permanently lockable memory that is located outside of a main memory array space. The unique code is compared to at least one component code. Use of the electronic system is controlled based on a predefined relationship between the unique code and the component code.

Abstract: An interface for a read-while-write memory. A memory device includes a single-chip memory array and an interface that is responsive to one or more commands to configure the memory array in a read-while-write configuration.

Abstract: An apparatus for protecting memory blocks in a block-based flash Erasable Programmable Read Only Memory (EPROM) device is disclosed. A non-volatile memory array includes a number of blocks that are capable of being placed in a locked state or an unlocked state. A volatile lock register and transmits a write protect signal and a volatile lock-down register are coupled to a lockable block in the volatile memory array. A hardware override line is coupled to both the lock register and the lock-down register. The hardware override line temporarily overrides operation of the lock-down register when it transmits a signal at a first logic state. The lock down register may be used to prevent programming of an associated lock register. The lock registers and lock down registers may be embodied in static access memory (SRAM) circuits.

Abstract: A programmable logic device that includes a voltage input and a detection circuit coupled to the voltage input is described. The detection circuit detects whether a voltage applied to the voltage input exceeds a predetermined value. The programmable logic device also includes a configuration circuit coupled to the detection circuit. The configuration circuit configures the programmable logic device to receive a current sufficient for program and erase operations through the voltage input in response to the detection circuit detecting that the voltage exceeds the predetermined value.

Abstract: A method and apparatus for partitioning a flash memory device is provided. The flash memory device includes a plurality of partitions, each partition able to be read, written, or erased simultaneously with the other partitions.

Abstract: A low-power interface for nonvolatile writeable memory is described. The interface includes an input buffer and an output buffer. The input buffer receives input signals having one of a number of pairs of logic levels. The input buffer is coupled to the nonvolatile writeable memory and coupled to the same power supply as the nonvolatile writeable memory. The input buffer translates the input signals received to the signal level used by the nonvolatile writeable memory. The output buffer is coupled to the nonvolatile writeable memory and is coupled to a different power supply from the input buffer and the nonvolatile writeable memory. The output buffer translates the signals received from the nonvolatile writeable memory to the same signal levels as the input signal. The input buffer and output buffer utilize input/output signals having logic levels compatible with complementary metal-oxide semiconductor (CMOS) technology.

Abstract: A high-speed output buffer for a nonvolatile writeable memory is described. The high-speed output buffer receives signals from the nonvolatile writeable memory having a pair of logic levels. The high-speed output buffer provides output signals having a pair of logic levels that may differ from the pair of logic levels of the signal received from the nonvolatile writeable memory. The high-speed output buffer comprises two inverters, a pull-up device, and a circuit with a relatively low voltage drop. The circuit with the relatively low voltage drop causes the high-speed output buffer to receive signals having one pair of logic levels while providing high-speed output signals having another pair of logic levels which may differ from the pair of logic levels of the received signal. The high-speed output buffer is coupled to a different power supply output from the nonvolatile writeable memory.

Abstract: A power supply lockout circuit that prevents corruption of nonvolatile writeable memory data is described. The power supply lockout circuit monitors the power supply signals from several power supplies. The power supply lockout circuit locks out commands writing to the nonvolatile writeable memory when any one of the monitored power supply signals coupled to the nonvolatile writeable memory is below a specified signal level. The power supply lockout circuit includes a detector which provides a lockout signal to the nonvolatile writeable memory when a power supply signal is less than a prespecified voltage. The power supply lockout circuit also includes a sampling circuit which provides other lockout signals to the nonvolatile writeable memory when a different power supply signal is less than a reference voltage.

Abstract: A nonvolatile memory includes a memory array and a buffer circuit for applying data read from the memory array to external circuitry. A compensation circuit is coupled to the buffer circuit for providing output compensation to the buffer circuit when enabled. The buffer circuit has (1) a first output speed when the compensation circuit is enabled and (2) a second output speed when the compensation circuit is disabled. A configuration circuit is coupled to the compensation circuit for selectively enabling the compensation circuit such that the buffer circuit can be configured between the first and second output speeds. A method of configuring a nonvolatile memory between a first output speed and a second output speed is also described.

Abstract: An integrated circuit arrangement for providing programming voltages to a flash EEPROM memory array including an arrangement for selecting subsets of bits of a word which is to be programmed and applying programming voltages only to the memory transistors of a selected subset.

Abstract: An integrated circuit which provides an arrangement by which the source of voltage for erasing the flash EEPROM memory array is detected and, if the source is a charge pump, the current provided is held to a constant lower value while, if the source is an external high voltage source, then the current is allowed to flow freely without regulation except by the size of a field effect transistor device in the path from the source of voltage to the memory array. In this manner, the circuitry is adapted to function with either internal or external power sources without paying a performance penalty for either type of operation.

Abstract: An integrated circuit which provides an arrangement by which the source of voltage for erasing the flash EEPROM memory array is detected and, if the source is a charge pump, the current provided is held to a constant lower value while, if the source is an external high voltage source, then the current is allowed to flow freely without regulation except by the size of a field effect transistor device in the path from the source of voltage to the memory array. In this manner, the circuitry is adapted to function with either internal or external power sources without paying a performance penalty for either type of operation.

Abstract: An integrated circuit arrangement for providing erase voltages to a flash EEPROM memory array including one charge pump for generating a first high voltage with substantial current which may be used for application to the source terminals of flash EEPROM memory cells during erase and to the gate terminals of flash EEPROM memory cells during programming, and another charge pump for generating a second lower voltage which may be used for application to the drain terminals of flash EEPROM memory cells during programming.

Abstract: A mechanism to change the functionality of a state machine used to control operation of an EPROM device. The mechanism is programmed to generate logic level signals which are input to combinatorial logic used to implement the state machine to cause the state machine to operate with a predetermined number of wait states (typically on, two or three wait states) depending on the programming applied to the mechanism. The mechanism utilizes EPROM cells which are covered by a shield so that once programmed, they cannot be erased. The programming is performed after the part has been manufactured, but before shipment to a customer who, upon receipt of the part programs the EPROM in the usual manner. The programmed EPROM can then be erased nd reprogrammed without affecting the programming defining the number of wait states generated during operation of the state machine.

Abstract: The method of testing a memory array of SRAM cells each of which includes memory transistors, bit and bit# lines, precharge circuitry, and an output test terminal involving the steps of connecting selected bit and bit# lines of selected SRAM cells to the output test terminal, disconnecting the memory transistors of the selected SRAM cells from the bit and bit# lines, disconnecting the bit and bit# lines from the precharge circuitry, enabling the column select circuitry to select the columns of the selected SRAM cells, applying a preselected level voltage to the output test terminal, and measuring any current which flows.

Abstract: A port expander for providing an external memory to be used with a microcontroller but recapturing the use of I/O ports which are lost due to the coupling of the memory. Two ports are coupled to the microcontroller for transfer of address and data information. An EPROM in the port expander provides the external memory while a special function register is used to couple data to and from two I/O ports. A configuration register provides programmability of which address values address the memory and which address values address the special function registers.

Abstract: A circuit for providing digital output signals carrying large amounts of currents without generating large transients including apparatus for providing a first current path for providing current at a first rate and a first polarity, apparatus for providing a second current path for providing current at the first rate and the first polarity after a first delay, and apparatus for providing a third current path for providing current of the first polarity at a rate greater than the first rate and sufficient for a load connected thereto after a second delay equal to the first delay whereby the current available at the load has built to a level sufficient to sustain the load prior to the provision of the third current.