powerSTEP01
Programming manual
The KVAL_DEC register contains the starting KVAL value that can be assigned to the PWM
modulators during deceleration (compensations excluded).
The available range is from 0 to 0.996 x VS with a resolution of 0.004 x VS, as shown in
Table 15.
Table 15. Voltage amplitude regulation registers
KVAL_X [7..0]
Output voltage
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
VS x (1/256)
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
1
VS x (254/256)
VS x (255/256)
11.1.11 INT_SPEED
This register is specific for voltage mode driving (see Section 8).
The INT_SPEED register contains the speed value at which the BEMF compensation curve
changes slope (Section 8.4 for details). Its value is expressed in step/tick and to convert it in
[step/s] the following formula can be used:
Equation 10
INT_SPEED ⋅ 2–18
[step/s]= -------------------------------------------------
tick
where INT_SPEED is the integer number stored in the register and tick is 250 ns.
The available range is from 0 to 976.5 step/s with a resolution of 0.0596 step/s.
Any attempt to write the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (Section 11.1.28).
11.1.12 ST_SLP
This register is specific for voltage mode driving (see Section 8).
The ST_SLP register contains the BEMF compensation curve slope that is used when the
speed is lower than the intersect speed (Section 8.4). Its value is expressed in s/step and
the available range is from 0 to 0.004 with a resolution of 0.000015.
When ST_SLP, FN_SLP_ACC and FN_SLP_DEC parameters are set to zero, no BEMF
compensation is performed.
Any attempt to write the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (Section 11.1.28).
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