Arm Limited

Wang-Kun Chen

Yew Keong Chong

Gus Wai-Yan Yeung

Sriram Thyagarajan

A memory device comprises an array of bitcells arranged as a plurality of rows of bitcells and a plurality of columns of bitcells, and has a plurality of wordlines and a plurality of readout channels. A control unit is configured to control access to the array of bitcells, wherein in response to a memory access request specifying a memory address the control unit is configured to activate a selected wordline and to activate the plurality of readout channels, and to access a row of bitcells in said array storing a data word and addressed by the memory address. The data word consists of a number of data bits given by a number of bitcells in each row of bitcells. The control unit is further configured to be responsive to a masking signal and, when the masking signal is asserted when said memory access request is received, the control unit is configured to activate only a portion of the selected wordline and a portion of the plurality of readout channels, such that only a portion of the data word is accessed.

Memory access control in a memory device

A memory has a normal mode and a power saving mode. The memory has bitline precharge circuitry which during the normal mode selectively couples a pair of bitlines to a precharge node to charge the bitlines to a given voltage level. During the power saving mode the bitlines are isolated from the precharge node. Voltage control circuitry is provided to maintain the precharge node at a first voltage level during the normal mode and at a second voltage level less than the first voltage level during the power saving mode. By reducing the voltage level at the precharge node during the power saving mode, the amount of inrush current occurring when switching from power saving mode to normal mode can be reduced, and this enables the wakeup time to be reduced when returning from power saving mode to normal mode.

Memory having power saving mode

A ternary content addressable memory (TCAM) has at least one TCAM cell comprising first and second memory bitcells for storing first and second bit values representing a cell state comprising one of a first cell state, a second cell state and a mask cell state. The first and second memory bitcells share a pair of bitlines for accessing the first and second bit values. Access control circuitry is provided for triggering, in response to a clock signal, a read or write access to the first memory bitcell during a first portion of a clock cycle and triggering a read access or write access to the second read bitcell during a second portion of the clock cycle.

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Austin, TX, United States of America

Wang-Kun Chen