Before spinning a BLDC motor, there are many driver settings that must be configured and tuned appropriately for the motor system to be robust and efficient. For example, some of these settings can be overcurrent protection thresholds, gate drive current settings, or PWM input mode. TI BLDC motor drivers offer a variety of interfaces to simplify configuring settings, diagnose motor faults, or even control the motor itself. The 4 interfaces supported are Serial Peripheral Interface (SPI), Hardware (H/W), Inter-inter communication (I²C), and Texas Instruments SPI (tSPI).

SPI – SPI interfaces use a traditional 4-wire SPI protocol and up to 10 MHz clock speed to read/write data to one or more motor driver devices. SPI devices allow for configurability of many motor settings in control register maps and allow for detailed fault diagnosis in status register maps.

H/W – Hardware interfaces use 2-5 dedicated pins set by external resistors to configure driver settings. On some devices, the hardware pins replace the SPI wires with four adjustable settings, and many other settings are fixed internally in the device. Hardware devices help simplify the motor driver design and development process.

I²C - I²C devices uses only two wires with external pullup resistors to configure multiple devices up to 400 kHz maximum frequency. These devices offer configurable settings and fault diagnosis through control and status registers.

tSPI – tSPI interface uses a traditional 4-wire SPI interface to control up to 15 motors independently. tSPI commands gives PWM duty cycle and frequency information for each addressable tSPI device to control each motor. This interface reduces the number of control wires for 3-phase motors by (N*6)-4 and significantly reduces the system size.

Table 2-3 gives a quick comparison of which families include which interfaces.