Seagate Fibre Channel Interface - Manual (Page 35)

Fibre Channel Interface Manual, Rev. D 21
Note. There are six sequences that invoke loop initialization. There is no operational difference between
them except that bytes 3 and 4 identify the reason for the loop initialization.
Loop initialization, no valid AL_PA (LIP)
The L_Port is attempting to acquire an AL_PA.
Loop initialization, loop failure, no valid AL_PA (LIP)
The transmitting L_Port detects a loop failure at its receiver. Since it has not completed initialization, it uses ‘F7’
(D23.7) rather than a valid AL_PA.
Loop initialization, valid AL_PA (LIP)
The L_Port is attempting to reinitialize the loop to a known state after recognizing a problem (performance deg-
radation).
Loop initialization, loop failure, valid AL_PA (LIP)
The transmitting L_Port detects a loop failure at its receiver.
Loop initialization reset (LIP)
If the rightmost two bytes consist of a valid destination and source address, the source is requesting the target
to perform a device reset.
Loop initialization reset all (LIP)
If byte 3 is FFh and byte 4 is a valid source address, the source is requesting all receiving targets to perform a
device reset.
Loop port enable (LPEyx)
LPEyx resets the bypass circuit and enables a previously-bypassed L_Port.
Loop port enable all (LPEfx)
LPEfx resets the bypass circuits on all L_Ports on the loop.
Loop port bypass (LPByx)
LPByx activates the port bypass circuit and prevents the L_Port from actively participating on the loop.
Loop port bypass all (LPBfx)
LPBfx activates the port bypass circuit for all L_Ports on the loop with bypass circuits except for the source of
the LPBfx.