Datasheet
DocID022729 Rev 3 59/70
L6472 Programming manual
70
This command can only be given when the previous motion command has been completed
(BUSY flag released).
Any attempt to perform a GoTo command when a previous command is under execution
(BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to rise
(see Section 9.1.19 on page 52).
9.2.9 GoTo_DIR (DIR, ABS_POS)
The GoTo_DIR command produces a motion to the ABS_POS absolute position imposing
a forward (DIR = '1') or a reverse (DIR = '0') rotation. The ABS_POS value is always in
agreement with the selected step mode; the parameter value unit is equal to the selected
step mode (full, half, quarter, etc.).
The GoTo_DIR command keeps the BUSY flag low until the target speed is reached. This
command can only be given when the previous motion command has been completed
(BUSY flag released).
Any attempt to perform a GoTo_DIR command when a previous command is under
execution (BUSY low) causes the command to be ignored and the NOTPERF_CMD flag to
rise (see Section 9.1.19).
9.2.10 GoUntil (ACT, DIR, SPD)
The GoUntil command produces a motion at SPD speed imposing a forward (DIR = '1') or
a reverse (DIR = '0') direction. When an external switch turn-on event occurs (see
Section 6.13 on page 30), the ABS_POS register is reset (if ACT = '0') or the ABS_POS
register value is copied into the MARK register (if ACT = '1'); the system then performs a
SoftStop command.
The SPD value is expressed in step/tick (format unsigned fixed point 0.28) which is the
same format as the SPEED register (see Section 9.1.4 on page 42).
The SPD value should be lower than MAX_SPEED and greater than MIN_SPEED,
otherwise the target speed is imposed at MAX_SPEED or MIN_SPEED respectively.
Table 42. GoTo_DIR command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 1 1 0 1 0 0 DIR From host
X X ABS_POS (Byte 2) From host
ABS_POS (Byte 1) From host
ABS_POS (Byte 0) From host
Table 43. GoUntil command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1 0 0 0 ACT 0 1 DIR From host
X X X X SPD (Byte 2) From host
SPD (Byte 1) From host
SPD (Byte 0) From host