Abstract: A memory array with RAM and embedded ROM including multiple RAM cells, a ROM cell, and a ROM enable circuit. Each RAM cell has a RAM cell structure with a first and second power terminals and configured to operate as a RAM cell when the memory array is in a RAM mode. The ROM cell has the same RAM cell structure in which at least one transistor is modified to cause the ROM cell to have a predetermined logic state. The ROM enable circuit enables bit lines of the ROM cell to control supply voltages provided to the power terminals of the RAM cells so that they settle to predetermined logic states in a ROM mode. The modified transistor has a pseudo transistor structure having a modified substrate that operates as a resistance, such as a doping region in the substrate having the same polarity type as the substrate.

Abstract: High-speed address fault detection is described that uses a split address ROM (read only memory) for address fault detection in split array memory systems. In one aspect, a disclosed embodiment includes separate arrays of memory cells having a plurality of wordlines and being configured to be accessed based upon a wordline address. Two or more separate address ROMs are also provided with each address ROM being associated with a different one of the separate arrays and being configured to provide outputs based upon only a portion of the wordline address. Detection logic is coupled to the outputs from the address ROMs and is configured to provide one or more fault indicator outputs to indicate whether an address fault associated with the wordline address has occurred. The outputs form the address ROMs can also be used for wordline continuity fault detection. Other embodiments are also described.

Abstract: A semiconductor memory device and method of operation are provided for a multi-bank memory array (100) with an address fault detector circuit (24, 28) connected to split word lines (WLn-WLm) across multiple banks, where the address fault detector circuit includes at least a first MOSFET transistor (51-54) connected to each word line for detecting an error-free operation mode and a plurality of different transient address faults including a “no word line select,” “false word line select,” and “multiple word line select” failure mode at one of the first and second memory banks. In selected embodiments, the address fault detector provides resistive coupling (33-40) between split word lines across multiple banks to create interaction or contention between split word lines to create a unique voltage level on a fault detection bit line during an address fault depending on the fault type.

Abstract: A memory array with RAM and embedded ROM including multiple RAM cells, a ROM cell, and a ROM enable circuit. Each RAM cell has a RAM cell structure with a first and second power terminals and configured to operate as a RAM cell when the memory array is in a RAM mode. The ROM cell has the same RAM cell structure in which at least one transistor is modified to cause the ROM cell to have a predetermined logic state. The ROM enable circuit enables bit lines of the ROM cell to control supply voltages provided to the power terminals of the RAM cells so that they settle to predetermined logic states in a ROM mode. The modified transistor has a pseudo transistor structure having a modified substrate that operates as a resistance, such as a doping region in the substrate having the same polarity type as the substrate.

Abstract: A semiconductor memory device and method of operation are provided for a multi-bank memory array (100) with an address fault detector circuit (24, 28) connected to split word lines (WLn-WLm) across multiple banks, where the address fault detector circuit includes at least a first MOSFET transistor (51-54) connected to each word line for detecting an error-free operation mode and a plurality of different transient address faults including a “no word line select,” “false word line select,” and “multiple word line select” failure mode at one of the first and second memory banks. In selected embodiments, the address fault detector provides resistive coupling (33-40) between split word lines across multiple banks to create interaction or contention between split word lines to create a unique voltage level on a fault detection bit line during an address fault depending on the fault type.

Abstract: High-speed address fault detection is described that uses a split address ROM (read only memory) for address fault detection in split array memory systems. In one aspect, a disclosed embodiment includes separate arrays of memory cells having a plurality of wordlines and being configured to be accessed based upon a wordline address. Two or more separate address ROMs are also provided with each address ROM being associated with a different one of the separate arrays and being configured to provide outputs based upon only a portion of the wordline address. Detection logic is coupled to the outputs from the address ROMs and is configured to provide one or more fault indicator outputs to indicate whether an address fault associated with the wordline address has occurred. The outputs form the address ROMs can also be used for wordline continuity fault detection. Other embodiments are also described.

Abstract: An integrated circuit includes a memory cell and a sense amplifier coupled to the memory cell via a first bit line and a second bit line. The sense amplifier includes first and second inverters cross-coupled to provide a latch. The first inverter is responsive to a first data signal provided by the memory cell over the first bit line. The second inverter is responsive to a second data signal as provided by the memory cell over the second bit line. A first negative bias temperature instability (NBTI) compensation transistor includes a source electrode coupled to receive a reference voltage, a drain electrode coupled to a source electrode of the first inverter, and a gate electrode coupled to first logic responsive to the first data signal.

Abstract: An integrated circuit includes a memory cell and a sense amplifier coupled to the memory cell via a first bit line and a second bit line. The sense amplifier includes first and second inverters cross-coupled to provide a latch. The first inverter is responsive to a first data signal provided by the memory cell over the first bit line. The second inverter is responsive to a second data signal as provided by the memory cell over the second bit line. A first negative bias temperature instability (NBTI) compensation transistor includes a source electrode coupled to receive a reference voltage, a drain electrode coupled to a source electrode of the first inverter, and a gate electrode coupled to first logic responsive to the first data signal.

Abstract: The present application discloses a memory array where each memory bit cell of the array includes a level shifter. In addition, each memory bit cell includes a write port that includes pass gate that can include a p-type field effect transistor and an n-type field effect transistor. The control electrodes of the p-type field effect transistor and the n-type field effect transistor are connected together as part of a common node. In addition, a current electrode of the p-type field effect transistor and a current electrode of the n-type field effect transistor are connected together to form a common node.

Abstract: A circuit has first latch, a second latch, a coupling circuit, and a power down circuit. The first latch has an input/output coupled to a data node. The second latch has an input/output. The coupling circuit is coupled between the input/output of the second latch and the data node. The coupling circuit is enabled during a normal operation of the circuit and disabled during a power down mode of the circuit. The power down control circuit is for disabling the first latch during the power down mode and for a time period after a transition from the power down mode to the normal operation. This allows the second latch to set the state of the first latch when transitioning from the power down mode to the normal mode. Thus normal operation can be fast, and the power down mode can have low leakage current.

Abstract: The present application discloses a memory array where each memory bit cell of the array includes a level shifter. In addition, each memory bit cell includes a write port that includes pass gate that can include a p-type field effect transistor and an n-type field effect transistor. The control electrodes of the p-type field effect transistor and the n-type field effect transistor are connected together as part of a common node. In addition, a current electrode of the p-type field effect transistor and a current electrode of the n-type field effect transistor are connected together to form a common node.

Abstract: A circuit has first latch, a second latch, a coupling circuit, and a power down circuit. The first latch has an input/output coupled to a data node. The second latch has an input/output. The coupling circuit is coupled between the input/output of the second latch and the data node. The coupling circuit is enabled during a normal operation of the circuit and disabled during a power down mode of the circuit. The power down control circuit is for disabling the first latch during the power down mode and for a time period after a transition from the power down mode to the normal operation. This allows the second latch to set the state of the first latch when transitioning from the power down mode to the normal mode. Thus normal operation can be fast, and the power down mode can have low leakage current.

Abstract: A static random access memory (14) has a normal mode of operation and a low voltage mode of operation. A memory array (15) includes memory cells (16) coupled to a first power supply node (VDD) for receiving a power supply voltage. A plurality of word line drivers is coupled to word lines of the memory array (15) and to a second power supply node (37). A word line driver voltage reduction circuit (36) has an input coupled to the first power supply node (VDD) and an output coupled to the second power supply node (37) for reducing a voltage on the output in relation to a voltage on the input in response to a low power supply voltage signal, and thus improving a static noise margin of the memory cells (16).

Abstract: A CMOS DRAM has an array in a well which is pumped to a voltage greater than the power supply voltage. The transfer devices of the memory cells in the array are of a conductivity type opposite to that of the well. The transfer devices each have a source/drain of the opposite conductivity type to that of the well which is connected to a bit line. The bit line will tend to rise in voltage at power-up which has the potential of forward biasing the PN junction between the source/drain and the well. The bit line rise is due to a word-line rise the rate of which is controlled so that the bit line rise does not exceed the rise in array voltage. The bit lines are ensured of being separated in voltage at the beginning of the first active cycle by enabling the N channel portion of the sense amplifier during power-up. The P channel portion of the sense amplifier is disabled during power-up to avoid too rapid of a rise in voltage on the bit lines.