L6470
Functional description
Doc ID 16737 Rev 2
29/64
6.17 BUSY\SYNC
pin
This pin is an open drain output which can be used as busy or synchronization signal
according to SYNC_EN bit value (STEP_MODE register).
6.17.1
BUSY operation mode
The pin works as busy signal when SYNC_EN bit is set low (default condition). In this mode
the output is forced low while a constant speed, absolute positioning or motion command is
under execution. The BUSY pin is released when command has been executed (target
speed or target position reached). The STATUS register includes a BUSY flag that is the
BUSY pin mirror (see paragraph
).
In case of daisy-chain configuration, BUSY pins of different ICs can be hard-wired to save
host controller GPIOs.
6.17.2
SYNC operation mode
The pin works as synchronization signal when SYNC_EN bit is set high. In this mode a step
clock signal is provided on output according to SYNC_SEL and STEP_SEL parameters
combination (see paragraph
).
6.18 FLAG
pin
By default an internal open drain transistor pulls the FLAG pin to ground when at least one
of the following conditions occurs:
●
Power-up or standby/reset exit,
●
Stall detection on A bridge,
●
Stall detection on B bridge,
●
Overcurrent detection,
●
Thermal warning,
●
Thermal shutdown,
●
UVLO,
●
Switch turn-on event,
●
Wrong command,
●
Non performable command.
It is possible to mask one or more alarm conditions by programming the ALARM_EN
register (see paragraph
). If the corresponding bit of ALARM_EN register is
low, the alarm condition is masked and it does not cause a FLAG pin transition; all other
actions imposed by alarm conditions are performed anyway. In case of daisy-chain
configuration, FLAG pins of different ICs can be or-wired to save host controller GPIOs.
