AMIS-30621 LIN Micro-stepping Motor Driver
Data Sheet
16.2 Application Commands
GetActualPos
This command is provided to the circuit by the LIN master to get the actual position of the stepper-motor. This position
(ActPos[15:0]) is returned in signed two’s complement 16-bit format. One should note that according to the programmed stepping
mode, the LSBs of ActPos[15:0] may have no meaning and should be assumed to be ‘0’, as described in Position Ranges.
GetActualPosalso provides a quick status of the circuit and the stepper-motor, identical to that obtained by command GetStatus
(see further).
Note: A GetActualPosition command will not attempt to reset any flag. GetActualPos corresponds to the following LIN reading frames.
1) Four data bytes in-frame response with direct ID (type #5)
Reading Frame
Byte
Content
Structure
Bit 7
*
ESW
Bit 6
*
Bit 5
1
Bit 4
0
Bit 3
ID3
Bit 2
ID2
Bit 1
ID1
Bit 0
ID0
0
1
2
3
Identifier
Data 1
Data 2
Data 3
Data 4
AD[6:0]
ActPos[15:8]
ActPos[7:0]
ElDef UV2
VddReset StepLoss
TSD
TW
Tinfo[1:0]
4
Where:
(*)
According to parity computation.
ID[5:0]:
Dynamically allocated direct identifier. There should be as many dedicated identifiers to this
GetActualPos command as there are stepper-motors connected to the LIN bus.
2) One preparing frame prior four data bytes in-frame response with 0x3D indirect ID
Preparing Frame
Byte
Content
Structure
Bit 4
Bit 7
Bit 6
Bit 5
Bit 3
Bit 2
Bit 1
Bit 0
*
1
1
*
0
ID4
ID3
ID2
ID1
ID0
0
1
2
Identifier
Data 1
Data 2
CMD[6:0] = 0x00
AD[6:0]
Reading Frame
Byte
Content
Structure
Bit 7
0
ESW
Bit 6
1
Bit 5
1
Bit 4
1
Bit 3
1
Bit 2
1
Bit 1
0
Bit 0
1
0
1
2
3
4
5
6
7
Identifier
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
Data 7
Data 8
AD[6:0]
ActPos[15:8]
ActPos[7:0]
VddReset StepLoss
ElDef
UV2
0xFF
0xFF
0xFF
0xFF
TSD
TW
Tinfo[1:0]
8
Where:
(*)
According to parity computation.
GetFullStatus
This command is provided to the circuit by the LIN master to get a complete status of the circuit and the stepper motor. Refer to RAM
Registers and Flags Table to see the meaning of the parameters sent to the LIN master.
Note: A GetFullStatus command will attempt to reset flags <TW>, <TSD>, <UV2>, <ElDef>, <StepLoss>, <CPFail>, <OVC1>,
<OVC2> and <VddReset>.
GetFullStatuscorresponds to two successive LIN in-frame responses with 0x3D indirect ID.
AMI Semiconductor – Sept. 2007, Rev 1.5
44
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