Datasheet

Programming manual L6470
58/70 Doc ID16737 Rev 5
9.2.4 GetParam (PARAM)
This command reads the current PARAM register value; PARAM is the respective register
address listed in Ta ble 1 2.
The command response is the current value of the register (most significant byte first). The
number of bytes making up the command response depends on the length of the target
register (see Table 12 ).
The returned value is the register one at the moment of GetParam command decoding. If
register values change after this moment, the response is not accordingly updated.
All registers can be read anytime.
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.
9.2.5 Run (DIR, SPD)
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).
Note: 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.
Table 40. GetParam command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0 0 1 PARAM from host
ANS Byte 2 (if needed) to host
ANS Byte 1 (if needed) to host
ANS Byte 0 to host
Table 41. Run command structure
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
0101000DIR from host
X X X X SPD (Byte 2) from host
SPD (Byte 1) from host
SPD (Byte 0) from host