The SmrDriver is the base module in MURC. There are 12 of them instantiated in the DE2-115 MURC design. Each one is capable of operating in a variety of ways – an amplifier, a phase shifter, a mixer, a lock-in amplifier, and most importantly, a phase-locked loop. Their behavior can be changed on the fly from the PC over ethernet.
A block diagram for the SmrDriver is given below.
Configurable parameters are generally denoted in green (muxes are also noted as green but their corresponding parameter names aren’t listed). Readable outputs are noted in blue (MURC can multicast any one of these).
Note that Q1 and Q2 are the quadrature signals, which can be used for frequency detection relative to a particular reference frequency when running the resonator in feedback.