Datasheet
Programming manual L6474
34/52 Doc ID 022529 Rev 3
9.1.1 ABS_POS
The ABS_POS register contains the current motor absolute position in agreement to the
selected step mode; the stored value unit is equal to the selected step mode (full, half,
quarter, etc.). The value is in 2's complement format and it ranges from -2
21
to +2
21
-1.
At power-on the register is initialized to “0” (HOME position).
9.1.2 EL_POS
The EL_POS register contains the current electrical position of the motor. The two MSbits
indicate the current step and the other bits indicate the current microstep (expressed in
step/128) within the step.
When the EL_POS register is written by the user the new electrical position is instantly
imposed. When the EL_POS register is written its value must be masked in order to match
with the step mode selected in the STEP_MODE register in order to avoid a wrong
microstep value generation (see Section 9.1.10); otherwise the resulting microstep
sequence is incorrect.
Any attempt to write the register when the outputs are enabled causes the command to be
ignored and the NOTPERF_CMD flag to rise (see Section 9.1.13).
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 TVAL
The TVAL register contains the current value that is assigned to the torque regulation DAC.
The available range is from 31.25 mA to 4 A with a resolution of 31.25 mA, as shown in
Tabl e 2 .
h19 STATUS Status 16 XXXX
(2)
High impedance state,
UVLO/Reset flag set.
R
h1A RESERVED Reserved address
h1B RESERVED Reserved address
1. R: Readable, WH: writable only when outputs are in high impedance, WR: always writable.
2. According to startup conditions.
Table 9. Register map (continued)
Address
[Hex]
Register
name
Register function Len. [bit]
Reset
Hex
Reset Value
Remarks
(1)
Table 10. EL_POS register
Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
STEP MICROSTEP