AMIS30623C623BRG Datasheet, PDF (38/61 Pages) ON Semiconductor – Micro-stepping Motor Driver

AMIS−30623
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 AMIS−30623 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 in−frame 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 AMIS−30623, 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 AMIS−30623 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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