L6470HTR View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'L6470HTR' PDF : 73 Pages View PDF
Programming manual
L6470
9.2.5
Any attempt to read an inexistent register (wrong address value) causes the command to be
ignored and the WRONG_CMD flag to rise at the end of the command byte as if an
unknown command code were sent.
Run (DIR, SPD)
Bit 7
0
X
Bit 6
1
X
Bit 5
0
X
Table 41. Run command structure
Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
1
0
0
0
DIR
X
SPD (Byte 2)
SPD (Byte 1)
SPD (Byte 0)
From host
From host
From host
From host
Note:
9.2.6
The Run command produces a motion at SPD speed; the direction is selected by the DIR
bit: '1' forward or '0' reverse. The SPD value is expressed in step/tick (format unsigned fixed
point 0.28) that 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 Run command is executed at MAX_SPEED or MIN_SPEED respectively.
This command keeps the BUSY flag low until the target speed is reached.
This command can be given anytime and is immediately executed.
StepClock (DIR)
Bit 7
0
Bit 6
1
Table 42. Stepclock command structure
Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0
1
1
0
0
DIR
From host
The StepClock command switches the device in Step-clock mode (see Section 6.7.5 on
page 26) and imposes the forward (DIR = '1') or reverse (DIR = '0') direction.
When the device is in Step-clock mode, the SCK_MOD flag in the STATUS register is raised
and the motor is always considered stopped (see Section 6.7.5 and Section 9.1.22 on page
55).
The device exits from Step-clock mode when a constant speed, absolute positioning or
motion command is sent through SPI. Motion direction is imposed by the respective
StepClock command argument and can by changed by a new StepClock command without
exiting Step-clock mode.
Events that cause bridges to be forced into high impedance state (overtemperature,
overcurrent, etc.) do not cause the device to leave Step-clock mode.
The StepClock command does not force the BUSY flag low. This command can only be
given when the motor is stopped. If a motion is in progress, the motor should be stopped
and it is then possible to send a StepClock command.
Any attempt to perform a StepClock command when the motor is running causes the
command to be ignored and the NOTPERF_CMD flag to rise (see Section 9.1.22).
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