Abstract: Circuits and methods for transmitting and receiving small swing differential voltage data to and from a memory are described. A plurality of memory cells is formed in arrays within a plurality of memory banks. Each memory bank is coupled to a pair of small swing differential voltage global bit lines that extend across the memory. A small signal write driver circuit is coupled to the global bit lines and configured to output a small signal differential voltage on the global bit lines during write cycles. A global sense amplifier is coupled to the global bit line pairs and configured to output a full swing voltage on a data line during a read cycle. Methods for providing small swing global bit line signals to memory cells are disclosed. The use of small swing differential voltage signals across the memory reduces power consumption and shortens memory cycle time.

Abstract: Apparatus and methods for providing a high density memory array with reduced read access time are disclosed. Multiple split bit lines are arranged along columns of adjacent memory bit cells. A multiple input sense amplifier is coupled to the multiple split bit lines. The loading on the multiple split bit line is reduced, and the corresponding read speed of the memory array is enhanced over the prior art. The sense amplifier and the memory bit cells have a common cell pitch layout height so that no silicon area penalty arises due to the use of the multiple split bit lines and sense amplifiers. Increased memory array efficiency is achieved.

Abstract: A device includes a tag cache memory array; a pre-parity unit configured to receive an address, and calculate and output a pre-parity bit calculated from all bits of the address. A comparator is configured to compare a tag read from the tag cache memory array with the address, and output a read-hit bit. The read-hit bit is true when the tag and the address are identical, and is false when the tag and the address are not identical. The device further includes a simplified parity-check unit configured to receive and perform operations on the pre-parity bit, the read-hit bit, and a parity bit from the tag cache memory array, and to output a read-parity bit.

Abstract: Methods for determining the state of memory cells include using an asymmetric sense amplifier. The methods include sensing the voltages on bit line (BL) and bit line bar (BLB) signals by coupling the BL to a first output node of an imbalanced cross-coupled latch (ICL), the ICL outputting a logic low value if the a difference between the a voltage on the BL and a voltage on the BLB exceeds a threshold. Sensing the voltages includes providing at least a first and a second pull down field effect transistor (FET) each having a channel coupled between the first and second output nodes and a ground node, respectively, in a cross coupled arrangement, wherein the second pull down FET has a channel width that is greater than a channel width of the first pull down FET. Additional methods are disclosed.

Abstract: A system and method for fast detection of cache memory hits in memory systems with error correction/detection capability is provided. A circuit for determining an in-cache status of a memory address comprises an error detect unit coupled to a cache memory, a comparison unit coupled to the cache memory, a results unit coupled to the comparison unit, and a selection unit coupled to the results unit and to the error detect unit. The error detect unit computes an indicator of errors present in data stored in the cache memory, wherein the data is related to the memory address. The comparison unit compares the data with a portion of the memory address, the results unit computes a set of possible in-cache statuses based on the comparison, and the selection unit selects the in-cache status from the set of possible in-cache statuses based on the indicator.

Abstract: Sensing circuits for determining the state of memory cells include a sense amplifier. The sense amplifier includes an imbalanced cross-coupled latch (ICL), a first gate field effect transistor (FET) between a bit line (BL) and a first output node, and a second gate FET between a bit line inverse (BLB) and a second output node. The ICL includes a first pull down FET between the first output node and an enable FET connected to electrical ground, and a second pull down FET between the second output node and the enable FET. Channel widths of the second pull down FET and the second gate FET are greater than channel widths of the first pull down FET and the first gate FET to enhance the ability to detect a one (1) and a zero (0) stored in a memory cell connected to the sense amplifier.

Abstract: A pulse width timing includes a first complementary resistor-capacitor (RC) circuit having an input for receiving an input signal, and a second complementary RC circuit coupled to an output of the first complementary RC circuit, wherein the first and second complementary RC circuits cooperate to produce an output signal based on the input signal, the output signal being delayed and having an adjusted pulse width with respect to the input signal.

Abstract: Circuits and methods for transmitting and receiving small swing differential voltage data to and from a memory are described. A plurality of memory cells is formed in arrays within a plurality of memory banks. Each memory bank is coupled to a pair of small swing differential voltage global bit lines that extend across the memory. A small signal write driver circuit is coupled to the global bit lines and configured to output a small signal differential voltage on the global bit lines during write cycles. A global sense amplifier is coupled to the global bit line pairs and configured to output a full swing voltage on a data line during a read cycle. Methods for providing small swing global bit line signals to memory cells are disclosed. The use of small swing differential voltage signals across the memory reduces power consumption and shortens memory cycle time.

Abstract: An oscillator includes a positive power supply node for providing a positive power supply voltage; a capacitor; and a constant current source providing a first constant current and coupled to the positive power supply node. The first constant current is independent from the positive power supply node. The oscillator also includes a charging current source configured to provide a second constant current to charge the capacitor, wherein the second constant current mirrors the first constant current. The oscillator further includes a constant current source inverter having a third constant current mirroring the first constant current. The constant current source inverter is configured to control the oscillator to transition state at a constant state transition voltage.

Abstract: A system and method for fast detection of cache memory hits in memory systems with error correction/detection capability is provided. A circuit for determining an in-cache status of a memory address comprises an error detect unit coupled to a cache memory, a comparison unit coupled to the cache memory, a results unit coupled to the comparison unit, and a selection unit coupled to the results unit and to the error detect unit. The error detect unit computes an indicator of errors present in data stored in the cache memory, wherein the data is related to the memory address. The comparison unit compares the data with a portion of the memory address, the results unit computes a set of possible in-cache statuses based on the comparison, and the selection unit selects the in-cache status from the set of possible in-cache statuses based on the indicator.

Abstract: Sensing circuits for determining the state of memory cells include a sense amplifier. The sense amplifier includes an imbalanced cross-coupled latch (ICL), a first gate field effect transistor (FET) between a bit line (BL) and a first output node, and a second gate FET between a bit line inverse (BLB) and a second output node. The ICL includes a first pull down FET between the first output node and an enable FET connected to electrical ground, and a second pull down FET between the second output node and the enable FET. Channel widths of the second pull down FET and the second gate FET are greater than channel widths of the first pull down FET and the first gate FET to enhance the ability to detect a one (1) and a zero (0) stored in a memory cell connected to the sense amplifier.

Abstract: A static random access memory (SRAM) circuit includes a pair of complementary global bit-lines, and a pair of complementary local bit-lines. A global read/write circuit is coupled to, and configured to write a small-swing signal to, the pair of global bit-lines in a write operation. The SRAM circuit further includes a first multiplexer and a second multiplexer, each having a first input and a second input. The first input of the first multiplexer and the first input of the second multiplexer are coupled to different one of the pair of global bit-lines. A sense amplifier includes a first input coupled to an output of the first multiplexer, and a second input coupled to an output of the second multiplexer. The sense amplifier is configured to amplify the small-swing signal to a full-swing signal, and outputs the full-swing signal to the pair of local bit-lines in the write operation.