46 Fibre Channel Interface Manual, Rev. D
8.2.2 Loop reinitialization
Loop reinitialization occurs when an L_Port is added to the loop, removed from the loop, or for error recovery.
Figure 12. Loop state machine (simplified)
8.3 Accessing another L_Port
Each port has its own private arbitration primitive (ARBx) signal. Each port uses this ARBx signal to arbitrate
for and win access rights to the loop. This must be done before communicating with another port.
When an L_Port is not communicating with another port, it is in a monitoring state to see if some other L_Port
is trying to communicate with it. The L_Port is also retransmitting the stream of transmission words it is receiv-
ing. If a port needs to communicate, it sends out its arbitration primitive signal by replacing the fill words1
between frames. If the arbitration primitive signal (ARBx) travels completely around the loop without being
1Fill words may be Idles, ARBx’s, or ARB(F0)’s. Fill words are transmitted between frames and may be deleted for clock
skew management purposes.
OLD-PORTINITIALIZATION
MONITORING
Received CLS
REQ(arbritrate as x) REQ(monitor)
(when allowed)
ARBITRATING
Rcvd my ARBx
ARB_PEN = 1
ARB_PEND = 1
Transmit OPNy|OPNr
Rcvd CLS
ARBITRATION
WON
Transmit CLS
Transmit
CLS
ENTER HERE
REQ(initialize)
REQ(old-port)
REQ(bypass L_Port)
TRANSFER
OPEN OPENED
Received CLS
Received OPNy
XMITTED
CLOSE
RECEIVED
CLOSE