AMIS-30621 Datasheet, PDF (43/59 Pages) AMI SEMICONDUCTOR – LIN Microstepping Motordriver

AMIS−30621
Usually, the AMIS−30621 makes use of dynamic
identifiers for general−purpose two, four or eight bytes
writing frames. If dynamic identifiers are used for other
purposes, this is acknowledged. Some frames implement a
<Broad> bit that allows addressing a command to all the
AMIS−30621 circuits connected to the same LIN bus.
<Broad> is active when at ‘0’, in which case the physical
address provided in the frame is thus not taken into account
by the slave nodes.
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 LSB’s of
<ActPos[15:0]> may have no meaning and should be
assumed to be ‘0’, as described in Position Ranges.
GetActualPos also provides a quick status of the circuit
and the stepper−motor, identical to that obtained by
command GetStatus (see further).
Note: A GetActualPos 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)
Table 30. READING FRAME
Byte
0
1
2
3
4
5
Content
Identifier
Data 1
Data 2
Data 3
Data 4
Checksum
Bit 7
*
ESW
V_DDReset
Bit 6
*
StepLoss
Bit 5
1
ElDef
Structure
Bit 4
Bit 3
0
ID3
AD[6:0]
ActPos[15:8]
ActPos[7:0]
UV2
TSD
Checksum over data
Bit 2
ID2
TW
Bit 1
ID1
Bit 0
ID0
Tinfo[1:0]
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.
Note: Bit 5 and bit 4 in byte 0 indicate the number of data bytes.
2. The master sends either a type#7 or type#8 preparing frame. After the type#7 or #8 preparing frame, the master sends
a reading frame type#6 to retrieve the circuit’s in−frame response.
Table 31. GetActualPos PREPARING FRAME TYPE #7
Byte
Content
Bit 7
Bit 6
Bit 5
0
Identifier
*
*
0
1
Data 1
1
2
Data 2
1
3
Checksum
Structure
Bit 4
Bit 3
Bit 2
ID4
ID3
ID2
CMD[6:0] = 0x00
AD[6:0]
Checksum over data
Bit 1
ID1
Bit 0
ID0
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