AMIS-30623 AMI Semiconductor, Inc., AMIS-30623 Datasheet - Page 45

• Manufacturer Part Number: AMIS-30623
• Description: Lin Microstepping Motordriver
• Manufacturer: AMI Semiconductor, Inc.

AMIS-30623 LIN Microstepping Motordriver
16.6.2. 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
• Indirect ID, which only specifies a reading command, the physical address of the slave node that must answer having been passed in
Notes
(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:
16.6.3. Preparing Frames
A preparing frame is a writing frame that warns a particular slave node that it will have to answer in the next frame (hence 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.
AMI Semiconductor – June 2006, Rev 3.0
node, thus triggering a specific command. This ID provides the fastest access to a read command but is forbidden for any other
action.
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.
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• Type #7: two data bytes writing frame with dynamically assigned identifier.
• Type #8: eight data bytes writing frame with 0x3C identifier.
• Type #5: 2, 4 or 8 Data bytes reading frame with a direct identifier dynamically assigned to a particular slave node together
• Type #6: 8 Data bytes reading frame with 0x3D identifier. This is intrinsically an indirect type, needing therefore a preparation
with an application command. A preparing frame is not needed.
frame. It has the advantage to use a reserved identifier.
Where:
(*)
Where:
AppCMD:
CMD[6:0]:
AD[6:0]:
Datan[7:0]:
Byte
0
1
2
Byte
0
1
2
3
4
5
6
7
8
Content
Identifier
Data 1
Data 2
Content
Identifier
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
Data 7
Data 8
According to parity computation
If = ‘0x80’ this indicates that Data 2 contains an application command
Application Command “byte”
Slave node physical address
Data transmitted
Bit 7
Bit 7
*
1
1
0
1
1
SetDualPositioning Writing Frame
Bit 6
Bit 6
*
0
Preparing Frame
45
Bit 5
Bit 5
0
1
AppCMD = 0x80
Data4[7:0]
Data5[7:0]
Data6[7:0]
Data7[7:0]
Data8[7:0]
Bit 4
Bit 4
ID4
Structure
Structure
1
CMD[6:0]
CMD[6:0]
AD[6:0]
AD[6:0]
Bit 3
Bit 3
ID3
1
Bit 2
Bit 2
ID2
1
Bit 1
Bit 1
ID1
0
Bit 0
Bit 0
ID0
0
Data Sheet