Control circuitry of a motor drive provides commands for operation of power circuitry based at least in part on signals exchanged with functional circuits, such as for system data and control data, such as feedback of motor or system parameters. The functional circuits may operate at different data rates, with different interrupt intervals, depending upon their capabilities. The control circuitry accommodates all of these flexibly. A physical backplane printed circuit board comprising independent data lines for each functional circuit allows for independent configuration of the data rates, interrupt intervals and communications between the control circuitry and the functional circuits.