Datasheet

Programming manual L6470
42/70 Doc ID16737 Rev 5
9.1.3 MARK
The MARK register contains an absolute position called MARK according to the selected
step mode; the stored value unit is equal to the selected step mode (full, half, quarter, etc.).
It is in 2's complement format and it ranges from -2
21
to +2
21
-1.
9.1.4 SPEED
The SPEED register contains the current motor speed, expressed in step/tick (format
unsigned fixed point 0.28).
In order to convert the SPEED value in step/s, the following formula can be used:
Equation 4
where SPEED is the integer number stored in the register and tick is 250 ns.
The available range is from 0 to 15625 step/s with a resolution of 0.015 step/s.
Note: The range effectively available to the user is limited by the MAX_SPEED parameter.
Any attempt to write the register causes the command to be ignored and the
NOTPERF_CMD flag to rise (see Section 9.1.22).
9.1.5 ACC
The ACC register contains the speed profile acceleration expressed in step/tick
2
(format
unsigned fixed point 0.40).
In order to convert ACC value in step/s
2
, the following formula can be used:
Equation 5
where ACC is the integer number stored in the register and tick is 250 ns.
The available range is from 14.55 to 59590 step/s
2
with a resolution of 14.55 step/s
2
.
When the ACC value is set to 0xFFF, the device works in infinite acceleration mode.
Any attempt to write to the register when the motor is running causes the command to be
ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22).
9.1.6 DEC
The DEC register contains the speed profile deceleration expressed in step/tick
2
(format
unsigned fixed point 0.40).
In order to convert DEC value in step/s
2
, the following formula can be used:
Equation 6
step/s[]
SPEED 2
28–
⋅
tick
----------------------------------------=
step/s
2
[]
ACC 2
40–
⋅
tick
2
-------------------------------=
step/s
2
[]
DEC 2
40–
⋅
tick
2
-------------------------------=