Reexen Technology Co., Ltd.

Minhao Yang

Hongjie Liu

Neil Webb

Alonso Morgado

Xiaofeng Yang

A mixed-signal in-memory computing sub-cell requires only 9 transistors for 1-bit multiplication. In one aspect, a computing cell is constructed from a plurality of such sub-cells that share a common computing capacitor and common transistors. As a result, the average number of transistors in each sub-cell is close to 6. Also proposed is a MAC array for performing MAC operations, which includes a plurality of the computing cells each activating the sub-cells therein in a time-multiplexed manner. Also proposed is an in-memory mixed-signal computing module for digitalizing parallel analog outputs of the MAC array and for performing other tasks in the digital domain.

Sub-cell, MAC array and bit-width reconfigurable mixed-signal in-memory computing module

A mixed-signal in-memory computing sub-cell only requires 9 transistors for 1-bit multiplication. A computing cell is constructed from a plurality of such sub-cells that share a common computing capacitor and a common transistor. A MAC array for performing MAC operations, includes a plurality of the computing cells each activating the sub-cells therein in a time-multiplexed manner. A differential version of the MAC array provides improved computation error tolerance and an in-memory mixed-signal computing module for digitalizing parallel analog outputs of the MAC array and for performing other tasks in the digital domain. An ADC block in the computing module makes full use of capacitors in the MAC array, allowing the computing module to have a reduced area and suffer from fewer computational errors.

Sub-cell, mac array and bit-width reconfigurable mixed-signal in-memory computing module

In one aspect, a time division interleaving band-pass filter can be used in voice activity detection, which operates at different central frequencies in respective intervals of a predetermined period of time. The band-pass filter circuitry includes multiple band-pass filtering channels sharing a common transistor circuit, bias circuit and current mirror circuit. The multiple band-pass filtering channels operate in a time division interleaving manner, which enables the sharing of the common set of band-pass filter circuitry components. Thus, the present invention allows a reduced chip area as the area does not increase proportionally with the number of filtering channels. The invention also mitigates the influence of transistor fabrication variations on the filter's central frequencies. Moreover, pulse durations tare additionally introduced to the determination of the central frequencies, dispensing with the need for matching of current mirror circuits and transistors and resulting in higher accuracy of the band-pass filter's central frequencies.

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Zürich, Switzerland

Minhao Yang