Cost Competitive ARCNET (ANSI 878.1) Controller with 2K x 8 On-Chip RAM
Power On
Reconfigure
Send
Timer has
Timed Out
Reconfigure
Burst
Read Node ID
Write ID to
RAM Buffer
1
Set NID=ID
N
Y
Start
Reconfiguration
Timer (6.72 S)*
Invitation
to Transmit to
this ID?
N
Y
Y
N
Free Buffer
Enquiry to
this ID?
TA?
Y
N
SOH?
Y
N
Transmit
NAK
RI?
Y
N
RI?
Transmit
ACK
Write SID
to Buffer
N
No Activity
for 656
uS?
Broadcast?
Y
Transmit
Free Buffer
Enquiry
N
Y
DID
=0?
No
Send
Packet
Y
Y
Activity
for 597.6
us?
Set NID=ID
N
N
N
Broadcast
Enabled?
Y
N
ACK?
DID
=ID?
Y
Start Timer:
T=(255-ID)
x 1.168 mS
Y
Y
N
Y
Was Packet
Broadcast?
N
Set TA
NAK?
Write Buffer
with Packet
1
N
Activity
Y
On Line?
No
Y
Pass the
Token
Activity
for 597.6
us?
Set TA
N
N
N
N
Figure 3.1 - COM20019I 3V OPERATION
CRC
OK?
N
T=0?
No
Increment
NID
Y
N
Y
Activity
for 597.6
us?
Y
N
Y
ACK?
Set TMA
LENGTH
OK?
Y
Y
DID
=0?
Set RI
-
-
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.
N
N
-
-
-
DID
SID refers to the source identification.
=ID?
DID refers to the destination identification.
Y
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 312.5 Kbps.
SEND ACK
SMSC COM20019I 3.3V Rev.C
Page 11
Rev. 10-31-06
DATASHEET
SMSC [ SMSC CORPORATION ]
