Datasheet

DocID023278 Rev 4 67/75
L6480 Programming manual
75
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
(Section 9.1.24 on page 59).
9.2.9 GoTo_DIR (DIR, ABS_POS)
The GoTo_DIR command produces a motion to 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 be given only 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 (Section 9.1.24).
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 (Section 6.14
on page 31), 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) that is the same
format as the SPEED register (Section 9.1.4 on page 45).
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 56. GoTo_DIR command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0110100DIRFrom host
X X ABS_POS (Byte 2) From host
ABS_POS (Byte 1) From host
ABS_POS (Byte 0) From host
Table 57. GoUntil command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1000ACT01DIR From host
X X X X SPD (Byte 2) From host
SPD (Byte 1) From host
SPD (Byte 0) From host