ZHCSDA7G July 2014 – February 2018 DRV10983
The DRV10983 can also command the speed through the I2C serial interface. To enable this feature, the OverRide bit is set to 1. When the DRV10983 is configured to operate in I2C mode, it ignores the signal applied to the SPEED pin.
The speed command can be set by writing the SpdCtrl and SpdCtrl[7:0] bits. The 9-bit SpdCtrl [8:0] located in the SpeedCtrl1 and SpeedCntrl2 registers are used to set the peak amplitude voltage applied to the motor. The maximum speed command is set when SpdCtrl [8:0] is set to 0x1FF (511).
When SpdCtrl  is written to the SpeedCtrl2 register, the data is stored, but the output is not changed. When SpdCtrl [7:0] is written to the SpeedCtrl1 register, the speed command is updated (see Figure 25).