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AMIS30623C623BRG Datasheet, PDF (38/61 Pages) ON Semiconductor – Micro-stepping Motor Driver | |||
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AMISâ30623
ID
ID0 ID1 ID2 ID3 ID4 ID5 ID6 ID7
Data1
command
NOTE: <ID4> and <ID5> indicate the number of data bytes.
ID5
ID4
Ndata (number of data fields)
0
0
2
0
1
2
1
0
4
1
1
8
Type #2: two, four or eight data bytes writing frame
with an identifier dynamically assigned to an
application command, regardless of the
physical address of the circuit.
Type #3: two data bytes writing frame with an
identifier dynamically assigned to a particular
slave node together with an application
command. This type of frame requires that
there are as many dynamically assigned
identifiers as there are AMISâ30623 circuits
using this command connected to the LIN bus.
Type #4: eight data bytes writing frame with 0x3C
identifier.
Reading Frames
A reading frame uses an inâframe response mechanism.
That is: the master initiates the frame (synchronization field
+ identifier field), and one slave sends back the data field
together with the check field. Hence, two types of identifiers
can be used for a reading frame:
⢠Direct ID, which points at a particular slave node,
indicating at the same time which kind of information is
awaited from this slave node, thus triggering a specific
command. This ID provides the fastest access to a read
command but is forbidden for any other action.
⢠Indirect ID, which only specifies a reading command,
the physical address of the slave node that must answer
having been passed in a previous writing frame, called
a preparing frame. Indirect ID gives more flexibility
than a direct one, but provides a slower access to a read
command.
Table 31. PREPARING FRAME #7
Byte
Content
Bit 7
Bit 6
Bit 5
0
Identifier
*
*
0
1
Data 1
1
2
Data 2
1
3
Checksum
Where:
(*) According to parity computation
Data2
Physical address
Broad
Data3...
Parameters...
1. A reading frame with indirect ID must always be
consecutive to a preparing frame. It will otherwise
not be taken into account.
2. A reading frame will always return the physical
address of the answering slave node in order to
ensure robustness in the communication.
The reading frames, used with the AMISâ30623, are the
following:
Type #5: two, four or eight Data bytes reading frame
with a direct identifier dynamically assigned to
a particular slave node together with an
application command. A preparing frame is not
needed.
Type #6: eight Data bytes reading frame with 0x3D
identifier. This is intrinsically an indirect type,
needing therefore a preparation frame. It has the
advantage to use a reserved identifier. (Note:
because of the parity calculation done by the
master, the identifier becomes 0x7D as physical
data over the bus).
Preparing Frames
A preparing frame is a frame from the master that warns
a particular slave node that it will have to answer in the next
frame (being a reading frame). A preparing frame is needed
when a reading frame does not use a dynamically assigned
direct ID. Preparing and reading frames must be
consecutive. A preparing frame will contain the physical
address of the LIN slave node that must answer in the
reading frame and will also contain a command indicating
which kind of information is awaited from the slave.
The preparing frames used with the AMISâ30623 can be
of type #7 or type #8 described below.
Type #7: two data bytes writing frame with
dynamically assigned identifier. The identifier
of the preparing frame has to be assigned to
ROM pointer 1000, see Table 34.
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
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