mc68hc912bd32 Freescale Semiconductor, Inc, mc68hc912bd32 Datasheet - Page 175

• Manufacturer Part Number: mc68hc912bd32
• Description: 16-bit Device Composed Of Standard On-chip Peripherals
• Manufacturer: Freescale Semiconductor, Inc

Byteflight™ Protocol
Byteflight™ Format
and Timing
5-sibus
IDLE
The BMW Byteflight™ protocol defines the message format, as follows:
The identifier (ID) byte is followed by the length (LEN) byte, which
contains the number of data bytes (0..12) of the message. Following the
data bytes (DATAn) are two CRC bytes (CRCH,CRCL), which contain
the checksum. The value zero is not allowed for any identifier (ID). The
priority of an identifier is inversely proportional to its value.
One byte of a message is embedded into a start bit (‘1’) and a stop bit
(‘0’), which are synchronization symbols and distinguish a message from
a SYNC pulse. The transfer starts with the MSB first. The dominant state
is represented by a logical ‘0’ and the recessive state is represented by
a logical ‘1’.
# BYTES:
Freescale Semiconductor, Inc.
IDLE
START
For More Information On This Product,
MESSAGE START
SEQUENCE
Figure 28 Byteflight™ Message Start Sequence
MSB
ID
Go to: www.freescale.com
1
Figure 26 Byteflight™ Message Format
Byteflight™ Module
Figure 27 Byteflight™ Byte Format
LEN
1
START
DATAn
0...12
ONE BYTE FRAME
ONE BYTE FRAME
MSB
t_bit
CRCH
1
CRCL
1
MC68HC912BD32 Rev 1.0
IDLE
Byteflight™ Protocol
Byteflight™ Module
LSB
LSB
STOP
STOP