AN2103 Freescale Semiconductor / Motorola, AN2103 Datasheet - Page 4

• Manufacturer Part Number: AN2103
• Description: Local Interconnect Network (LIN) Demonstration
• Manufacturer: Freescale Semiconductor / Motorola

4
Application Note
2.2 Response
Frame
2.3 Sleep Mode
Frame
NOTE:
NOTE:
START
BIT
Any slave node can bring the bus out of sleep mode (by transmitting the
WAKE_UP signal). However, it is only the master that is allowed to put
the network to sleep.
allows low cost microcontrollers with internal RC oscillators to be used
in slave nodes.
Internal oscillators have a low tolerance that requires to be trimmed
(actively changed) if reliable communication is to be maintained.
The final part of the header is the IDENTIFIER FIELD that denotes the
content and length of a message. The content is represented by 6
identifier bits and 2 parity bits. Identifier bits ID4 and ID5 specify the
number of data fields in a message.
The parity information is calculated using a mixed parity algorithm that
prevents all bits being recessive or dominant.
The response frame is always transmitted by the slave task (this can be
the slave in the master). It consists between 2, 4 or 8 data fields and a
checksum field. The data fields consist of 8 bits of data transmitted LSB
first. The checksum contains an inverted modulo 256 sum over all data
bytes.
A reserved Sleep Mode Frame with a fixed 0x80 identifier was specified
in the original version of the LIN specification. In version 1.2 or later the
Sleep Mode Frame has been removed and replaced by reserved
identifiers, which are described in section 2.4. However, as the demo
software was developed to the original specification it uses the fixed
identifier 0x80 as the Sleep Mode Frame.
Refer to LIN specifications for further details.
ID0
Freescale Semiconductor, Inc.
For More Information On This Product,
ID1
Figure 3 Identifier Field
Go to: www.freescale.com
ID2
IDENTIFIER
ID3
FIELD
ID4
ID5
Figure 3
P0
P1
shows the identifier field.
MOTOROLA
AN2103