COM20020I-DZD Standard Microsystems (SMSC), COM20020I-DZD Datasheet - Page 11

• Manufacturer Part Number: COM20020I-DZD
• Manufacturer: Standard Microsystems (SMSC)

Specifications of COM20020I-DZD

• Number Of Transceivers: 1
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (typ): 5V
• Operating Supply Voltage (min): 4.5V
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Compliant

5Mbps ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
Datasheet
SMSC COM20020I Rev D
-
-
-
-
-
* 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
Timer (420 mS)*
Reconfiguration
N
Broadcast?
Start
TA?
Was Packet
Broadcast?
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
Figure 3.1 - COM20020ID Operation
to Transmit to
Reconfigure
RAM Buffer
Write ID to
Set NID=ID
Read Node ID
Invitation
Power On
this ID?
Y
DATASHEET
Send
Burst
Increment
Free Buffer
RI?
Transmit
Enquiry
NID
Y
Y
ACK?
N
Y
Free Buffer
Enquiry to
N
N
this ID?
NAK?
Y
N
Page 11
for 37.4
Activity
for 37.4
Activity
No
us?
us?
N
No
1
N
Y
Set TA
N
Pass the
Y
Token
RI?
SEND ACK
Y
Write SID
to Buffer
Write Buffer
with Packet
N
LENGTH
DID
=0?
N
Y
Y
=ID?
CRC
OK?
SOH?
=ID?
OK?
1
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
On Line?
x 73 us
Activity
T=0?
for 41
uS?
Y
Revision 12-05-06
Y
N
Y
N