COM20020I-HD SMSC, COM20020I-HD Datasheet - Page 10

• Manufacturer Part Number: COM20020I-HD
• Description: Network Controller & Processor ICs ARCNET Contrllr
• Manufacturer: SMSC

Specifications of COM20020I-HD

• Product: Controller Area Network (CAN)
• Number Of Transceivers: 1
• Data Rate: 5 Mbps
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Supply Current (max): 40 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

SMSC COM20020I 3.3V Rev.E
5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
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-
-
-
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* Reconfig timer is programmable via setup2 register bits 1, 0.
Note - All time values are valid for 5 Mbps.
ID refers to the identification number of the ID assigned to this node.
NID refers to the next identification number that receives the token
after this ID passes it.
SID refers to the source identification.
DID refers to the destination identification.
SOH refers to the start of header character; preceeds all data packets.
N
Reconfiguration
Timer (420 mS)*
N
Broadcast?
Start
Was Packet
Broadcast?
TA?
Packet
Send
for 37.4
Activity
ACK?
us?
No
N
N
Y
Reconfigure
Timer has
Timed Out
Y
Y
Y
N
Y
Set TMA
Transmit
Transmit
Set TA
NAK
ACK
Y
to Transmit to
Reconfigure
RAM Buffer
Write ID to
Set NID=ID
Invitation
Read Node ID
Power On
this ID?
Y
Figure 1 - COM20020I 3V Operation
Burst
Send
Increment
Free Buffer
Transmit
Enquiry
RI?
NID
Y
Y
ACK?
N
Y
Free Buffer
Enquiry to
DATASHEET
N
N
this ID?
NAK?
Y
N
for 37.4
Activity
for 37.4
Activity
No
us?
Page 10
N
us?
No
1
N
Y
Set TA
N
Pass the
Y
Token
RI?
SEND ACK
Y
Write Buffer
Write SID
to Buffer
with Packet
N
LENGTH
DID
=0?
N
Y
Y
=ID?
CRC
OK?
=ID?
OK?
1
SOH?
DID
=0?
DID
DID
N
Y
Y
N
Y
Y
N
N
N
N
Broadcast
Enabled?
Y
Set RI
N
N
Start Timer:
Set NID=ID
T=(255-ID)
No Activity
x 73 us
On Line?
Activity
T=0?
for 41
uS?
Y
Y
N
Revision 09-11-06
Y
N