Datasheet TB9120AFTG (Toshiba) - 9

TB9120AFTG 7.4 CLK input
The electrical angle advances by 1 for each CLK input. The signal is reflected at a rising edge. CLK input Function Goes to the next step at a rising edge. No change (stays in the previous state)
7.5 ENABLE circuit
Switches the motor drive outputs ON / OFF. When ENABLE input is turned from H to L under the standby mode released (BSTBY=H), constant current operation starts, an internal counter which is synchronized with CLK input moves forward and then a motor begins to run. Be sure to fix ENABLE pin to the L level during a power supply start-up and shutdown. ENABLE controls only switching ON/OFF the motor drive outputs. However, the internal counter proceeds because the internal logic circuit counter is stil working even when ENABLE=L; the outputs to drive a motor are turned off. ENABLE input Output MOSFETs H ON L OFF In addition, in the case where DIAG pin is latched to L level after either overcurrent detection or over temperature detection, refer to 7.10, the latch can be released by setting ENABLE pin to L level whose duration should be 0.2ms or more(Note). However, if an overcurrent state or an over temperature state continues, DIAG outputs L level again. Refer to 7.18 and 7.19. Note) Inspection for it is not conducted at the time of shipment. © 2020 9 2020-05-12 Toshiba Electronic Devices & Storage Corporation