Hello Kaizawa-san,
Please see below capture for DRV8832. I used the DRV8832EVM at 5V input. I hope this helps.
1) Vset = 10mV, measure Vmotor = 57mV
2) Vset = 50mV, measured Vmotor = 0.198V
3) Vset = 100mV, measured Vmotor = 0.38V
4) Vset = 150mV, measured Vmotor = 0.59V
