COM20019I3V-HT SMSC, COM20019I3V-HT Datasheet - Page 15

• Manufacturer Part Number: COM20019I3V-HT
• Description: Network Controller & Processor ICs ARCNET Contrllr
• Manufacturer: SMSC

Specifications of COM20019I3V-HT

• Product: Controller Area Network (CAN)
• Number Of Transceivers: 1
• Data Rate: 312.5 Kbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Supply Current (max): 25 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Package / Case: TQFP-48
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4.6.3
4.6.4
4.6.5
SMSC COM20019I 3.3V Rev.C
Cost Competitive ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
Data Packets
A Data Packet consists of the actual data being sent to another node. It is sent by the following sequence:
Acknowledgements
An Acknowledgement is used to acknowledge reception of a packet or as an affirmative response to FREE
BUFFER ENQUIRIES and is sent by the following sequence:
Negative Acknowledgements
A Negative Acknowledgement is used as a negative response to FREE BUFFER ENQUIRIES and is sent
by the following sequence:
BURST
ALERT
An ALERT BURST
An SOH (Start Of Header--ASCII code 01H)
An SID (Source ID) character
Two (repeated) DID (Destination ID) characters
A single COUNT character which is the 2's complement of the number of data bytes to follow if a
short packet is sent, or 00H followed by a COUNT character if a long packet is sent.
N data bytes where COUNT = 256-N (or 512-N for a long packet)
Two CRC (Cyclic Redundancy Check) characters. The CRC polynomial used is: X
An ALERT BURST
An ACK (ACKnowledgement--ASCII code 86H) character
An ALERT BURST
A NAK (Negative Acknowledgement--ASCII code 15H) character
SOH
SID
DID
ALERT BURST
ALERT BURST
DID
DATASHEET
Page 15
COUNT
ACK
NAK
data
data
CRC
16
CRC
+ X
15
Rev. 11-07-08
+ X
2
+ 1.