Iterative programming of analog content addressable memory
Embodiments of the disclosure provide a system, method, or computer readable medium for programming a target analog voltage range of an analog content addressable memory (aCAM) row. The method may comprise calculating a threshold current sufficient to switch a sense amplifier (SA) on and discharge a match line (ML) connected to a cell of the aCAM; and based on calculating the threshold current, programming a match threshold value by setting a memristor conductance in association with the target analog voltage range applied to a data line (DL) input. The target analog voltage range may comprise a target analog voltage range vector.
1. A circuit for efficiently implementing the programming method in hardware comprising:
an analog content addressable memory (aCAM) array;
a digital-to-analog converter (DAC) circuit block;
a pre charge circuit block (PC);
a programming circuit block (PM);
a sense amplifier circuit block (SA);
an AND gate; and
a digital signal processing (DSP) unit controlling the circuit.
2. The circuit of claim 1 , wherein the DAC circuit block receives a digital input and returns an analog output for a data line (DL) voltage and a voltage of the SA (V sense ).
3. The circuit of claim 1 , wherein the PC receives a clock value and returns a charge to a match line (ML) when the clock value is high.
4. The circuit of claim 1 , wherein the PM is a memristor conductance programming circuit block that executes an algorithm when triggered.
5. The circuit of claim 1 , wherein the SA returns a high value if the voltage on match line (ML) is higher than an output from the DAC circuit block.
6. The circuit of claim 1 , wherein the DSP unit controlling the circuit receives an End Of Programming (EOP) bit from the AND gate and stops the process based on the EOP bit.