AMIS-30621 Datasheet, PDF (38/59 Pages) AMI SEMICONDUCTOR – LIN Microstepping Motordriver

AMIS−30621
Table 25. PREPARING FRAME #7
Byte
Content
Bit 7
Bit 6
0
Identifier
*
*
1
Data 1
1
2
Data 2
1
3
Checksum
Where:
(*) According to parity computation
Bit 5
0
Structure
Bit 4
Bit 3
ID4
ID3
CMD[6:0]
AD[6:0]
Checksum over data
Bit 2
ID2
Bit 1
ID1
Bit 0
ID0
Type #8: eight data bytes preparing frame with 0x3C
identifier.
Table 26. PREPARING FRAME #8
Structure
Byte
Content
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
Identifier
0
0
1
1
1
1
0
0
1
Data 1
AppCMD = ...
2
Data 2
1
CMD[6:0]
3
Data 3
1
AD[6:0]
4
Data 4
Data4[7:0] FF
5
Data 5
Data5[7:0] FF
6
Data 6
Data6[7:0] FF
7
Data 7
Data7[7:0] FF
8
Data 8
Data8[7:0] FF
9
Checksum
Checksum over data
Where:
AppCMD: If = ‘0x80’ this indicates that Data 2 contains an application command
CMD[6:0]: Application Command “byte”
AD[6:0]: Slave node physical address
Datan[7:0]: Data transmitted
Dynamic Assignment of Identifiers
The identifier field in the LIN datagram denotes the
content of the message. Six identifier bits and two parity bits
are used to represent the content. The identifiers 0x3C and
0x3F are reserved for command frames and extended
frames. Slave nodes need to be very flexible to adapt itself
to a given LIN network in order to avoid conflicts with slave
nodes from different manufacturers. Dynamic assignment
of the identifiers will fulfill this requirement by writing
identifiers into the circuits RAM. ROM pointers are linking
commands and dynamic identifiers together. A writing
frame with identifier 0x3C issued by the LIN master will
write dynamic identifiers into the RAM. One writing frame
is able to assign 4 identifiers; therefore 3 frames are needed
to assign all identifiers. Each ROM pointer <ROMp_x
[3:0]> place the corresponding dynamic identifier
<Dyn_ID_x [5:0]> at the correct place in the RAM (see
Table below: LIN – Dynamic Identifiers Writing Frame).
When setting <Broad> to zero broadcasting is active and
each slave on the LIN bus will store the same dynamic
identifiers, otherwise only the slave with the corresponding
slave address is programmed.
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