  With the rise in in-memory computing architectures to reduce the
compute-memory bottleneck, a new bottleneck is present between analog and
digital conversion. Analog content-addressable memories (ACAM) are being
recently studied for in-memory computing to efficiently convert between analog
and digital signals. Magnetic memory elements such as magnetic tunnel junctions
(MTJs) could be useful for ACAM due to their low read/write energy and high
endurance, but MTJs are usually restricted to digital values. The spin orbit
torque-driven domain wall-magnetic tunnel junction (DW-MTJ) has been recently
shown to have multi-bit function. Here, an ACAM circuit is studied that uses
two domain wall-magnetic tunnel junctions (DW-MTJs) as the analog storage
elements. Prototype DW-MTJ data is input into the magnetic ACAM (MACAM) circuit
simulation, showing ternary CAM function. Device-circuit co-design is carried
out, showing that 8-10 weight bits are achievable, and that designing
asymmetrical spacing of the available DW positions in the device leads to
evenly spaced ACAM search bounds. Analyzing available spin orbit torque
materials shows platinum provides the largest MACAM search bound while still
allowing spin orbit torque domain wall motion, and that the circuit is
optimized with minimized MTJ resistance, minimized spin orbit torque material
resistance, and maximized tunnel magnetoresistance. These results show the
feasibility of using DW-MTJs for MACAM and provide design parameters.
