Programming manual
L6472
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DocID022729 Rev 5
9.1.9 FS_SPD
The FS_SPD register contains the threshold speed. When the actual speed exceeds this
value the step mode is automatically switched to full-step two-phase on. Its value is
expressed in step/tick (format unsigned fixed point 0.18) and to convert it in step/s the
following formula can be used.
Equation 6
If the FS_SPD value is set to h3FF (max.) the system always works in microstepping mode
(SPEED must go beyond the threshold to switch to full-step mode). Setting FS_SPD to zero
does not have the same effect as setting step mode to full-step two phase on: the zero
FS_SPD value is equivalent to a speed threshold of about 7.63 step/s.
The available range is from 7.63 to 15625 step/s with a resolution of 15.25 step/s.
9.1.10
TVAL_HOLD, TVAL_RUN, TVAL_ACC and TVAL_DEC
The TVAL_HOLD register contains the current value that is assigned to the torque
regulation DAC when the motor is stopped.
The TVAL_RUN register contains the current value that is assigned to the torque regulation
DAC when the motor is running at constant speed.
The TVAL_ACC register contains the current value that is assigned to the torque regulation
DAC during acceleration.
The TVAL_DEC register contains the current value that is assigned to the torque regulation
DAC during deceleration.
The available range is from 31.25 mA to 4 A with a resolution of 31.25 mA, as shown in
step s
FSSPD 0.5
+
2
18
–
tick
--------------------------------------------------------
=
Table 12. Torque regulation by TVAL_HOLD, TVAL_ACC, TVAL_DEC and TVAL_RUN
registers
TVAL_X [6 … 0]
Output current amplitude
0 0 0 0 0 0 0
31.25
mA
0 0 0 0 0 0 1
62.5
mA
…
…
…
…
…
…
…
…
1 1 1 1 1 1 0
3.969
A
1 1 1 1 1 1 1
4
A