COM20022I-3.3V Datasheet, PDF (10/73 Pages) SMSC Corporation – 10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Chip RAM

10 Mbps ARCNET (ANSI 878.1) Controller with 2Kx8 On-Chip RAM
Datasheet
Reconfigure
Timer has
Timed Out
Power On
Send
Reconfigure
Burst
Read Node ID
Write ID to
RAM Buffer
1
Set NID=ID
Start
Reconfiguration
Timer (210 mS)*
Y
Invitation
N
to Transmit to
this ID?
N
Y
TA?
Broadcast?
N
Y
Send
Packet
Transmit
NAK
Transmit
ACK
Y
Was Packet
Broadcast?
N
No
Activity
Y
for 18.7
us?
N
Set TA
N
Y
ACK?
Set TMA
Y
Free Buffer
Enquiry to
this ID?
Y
N
RI?
N
Y
N
SOH?
Y
N
RI?
Transmit
Free Buffer
Enquiry
N
Y
N
ACK?
No
Activity
for 18.7
us?
Y
N
NAK?
1
Write SID
to Buffer
Y
Set TA
DID ^Y
=0?
N
DID
=ID?
YN
Broadcast
Enabled?
Y
Write Buffer
with Packet
Pass the
Token
Increment
Y
No
Activity
N
NID
for 18.7
us?
CRC ^N
OK?
Y
LENGTH ^N
OK?
Y
- 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.
* Reconfig timer is programmable via setup2 register bits 1, 0.
Note - All time values are valid for 10Mbps.
Y
DID
=0?
N
DID ^N
=ID?
Y
SEND ACK
N
Set RI
No Activity
N
for 20.5
uS?
Y
Set NID=ID
Start Timer:
T=(255-ID)
x 36.5 us
Activity
Y
On Line?
N
N
T=0?
Y
Figure 3.1 - COM20022I 3V Operation
Revision 03-08-07
Page 10
DATASHEET
SMSC COM20022I 3.3V Rev.C