DESIGN OF A CUSTOM ASIC INCORPORATING CAN™ AND 1 ...

Cyclic Redundancy Check (CRC) FieldThe CRC Field is 16 bits long. It consists of a
CRC Sequence (15 bits) followed by a CRC delimiter (1 bit). The receiver uses the value
in the CRC Sequence field to check if the data bit sequence in the frame was corrupted
during delivery. The CRC delimiter is always a recessive bit.
Acknowledgement FieldThe Acknowledgement Field is two bits long. It contains the
Acknowledgement Slot bit and the Acknowledgement Delimiter Bit. The node that
transmits the Data Frame sends these two bits recessively. The transmitter expects at
least one receiver to acknowledge receipt of the transmitted message. Any node that
receives the message without error will overwrite the Acknowledgement Slot bit with a
dominant bit. The Acknowledge Delimiter bit always remains recessive to distinguish a
positive acknowledgement from the start of an Error Frame. If no receiver acknowledges
a message, the transmitter will continue to try to send the message until the sending node
turns itself off.
End-Of-Frame and Interframe SpaceEvery Data Frame ends with a seven-bit End-Of-
Frame Field and a three-bit Interframe Space. The End-Of-Frame Field must be
transmitted recessively to mark a completely error-free transmitted frame. If the
Acknowledgement Delimiter bit or any of the End-Of-Frame bits are transmitted
dominantly then this marks the beginning of an Error or Overload Frame. The Interframe
Space represents the minimum amount of spacing between adjacent Data or Remote
Frames. All three bits must be transmitted recessively. The bus may continue to remain
idle after this, or a new frame will be indicated with the dominant Start-Of-Frame bit. If
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