L6472 datasheet(25/69 Pages) STMICROELECTRONICS

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L6472

Functional description

Doc ID 022729 Rev 1

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6.7.3

Motion commands

Motion commands produce a motion in order to perform a user-defined number of

microsteps in a user-defined direction that are sent to the device together with the command

(see Figure 11).

The performed motor motion is compliant to programmed speed profile boundaries

(acceleration, deceleration, minimum and maximum speed).

Note that with some speed profiles or motion commands, the deceleration phase can start

before the maximum speed is reached.

Figure 11.

Motion command examples

6.7.4

Stop commands

A stop command forces the motor to stop. Stop commands can be sent anytime.

The SoftStop command causes the motor to decelerate with a programmed deceleration

value until the MIN_SPEED value is reached and then stops the motor maintaining the rotor

position (a holding torque is applied).

The HardStop command stops the motor instantly, ignoring deceleration constraints and

maintaining the rotor position (a holding torque is applied).

The SoftHiZ command causes the motor to decelerate with a programmed deceleration

value until the MIN_SPEED value is reached and then forces the bridges into high-

impedance state (no holding torque is present).

The HardHiZ command instantly forces the bridges into high-impedance state (no holding

torque is present).

6.7.5

Step-clock mode

In step-clock mode the motor motion is defined by the step-clock signal applied to the STCK

pin.

At each step-clock rising edge, the motor is moved by one microstep in the programmed

direction and the absolute position is consequently updated.

When the system is in step-clock mode the SCK_MOD flag in the STATUS register is raised,

the SPEED register is set to zero and the motor status is considered stopped whatever the

STCK signal frequency (the MOT_STATUS parameter in the STATUS register equal to

g00h).

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