msm9225 Oki Semiconductor, msm9225 Datasheet - Page 56

• Manufacturer Part Number: msm9225
• Description: Can Controller Area Network Controller
• Manufacturer: Oki Semiconductor

6. Error control functions
(1) Types of errors
(2) Error frame output timing
(3) Procedure when an error is generated
¡ Semiconductor
Type of error
Form error
Stuff error
CRC error
Ack error
Bit error
After the error frame, the transmit node retransmits a data frame or a remote frame.
Bit error, stuff error,
form error, Ack error
CRC error
Type of error
Comparison of output
level and bus level
(excluding stuff bits)
Verify received data
with the stuff bit
CRC generated from
received data
compared to received
CRC sequence
Verify fixed format
field/frame
Verify Ack slot by
transmit node
Detection method Detection condition Transmit/Receive
Error description
Error frame is output at the next bit after the error is detected.
Error frame is output at the next bit after the Ack delimiter.
Both levels do not
match
Same level of data for
6 consecutive bits
CRC's do not match
Detection of fixed
format violation
Detection of a
"recessive" bit during
Ack slot
Output timing
Transmit/Receive
Transmit/Receive
Transmit node
Receive node
Receive node
node
node
Detection state
Bits that output data onto the
bus, start-of-frame to end-of-
frame, error frame, and
overload frame
Start-of-frame to CRC
saquence
Start-of-frame to data field
CRC delimiter
• Ack field
• End-of-frame
• Error frame
• Overload frame
Ack slot
Field/Frame
MSM9225
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