Hitachi HUS154530VLF400 User Manual

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

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The Loop Initialization Procedure is as follows... 

1.   Select Initial AL_PA 

The initial AL_PA is EFh. 

2.   Select a Loop Master 

LISM frames are continuously transmitted.  The D_ID and S_ID fields are set to 0000EFh. 

If a LISM frame is received which is the same as the one transmitted, the Port becomes the Loop Master and continues the 

procedure at step 3. 

For all other received LISM frames... 

-  If the D_ID is 000000h, the frame is retransmitted. 

-  If the Port_Name in the payload is greater than the Port_Name, the frame is discarded. 

-  If the Port_Name in the payload is less than the Port_Name, the frame is retransmitted. 

If an ARB(F0) is received, the Port continues the procedure at step 4. 

3.   Loop Master 

a.   ARB(F0) is continuously transmitted until ARB(F0) is received. 
b.   The Port prepares an LIFA frame with an initial AL_PA bit map of all zeros. After transmitting the LIFA frame, the 

Port waits to receive a LIPA frame. 

c.   The AL_PA bit map from the LIFA frame is used in a LIPA frame. If the bit corresponding to the Port’s previously 

assigned AL_PA is not set it is set now. If it is already set, the Port attempts to obtain its Hard AL_PA in step d. The 
Port transmits the LIPA and waits to receive it back. 

d.   The AL_PA bit map from the LIPA frame is used in a LIHA frame. If the bit corresponding to the Port’s hard 

assigned AL_PA is not set it is set now (unless a bit was set for LIPA). If it is already set, the Port attempts to obtain a 
Soft AL_PA in step e. The Port transmits the LIHA and waits to receive it back. 

e.   The AL_PA bit map from the LIHA frame is used in a LISA frame. If a bit was not set for LIHA, the bit associated 

with the lowest priority AL_PA still available is set. This is the Port’s “soft assigned” AL_PA. If no bits are available, 
the Port shall stay in non-participating mode. The Port transmits the LISA and waits to receive it back. If byte 3 of the 
payload in the received LISA frame is still 01h (indicating that all nodes on the loop support positional mapping) the 
drive continues with the next two steps. Otherwise, the next two steps are skipped. 

f.   The Port creates a LIRP frame with an AL_PA position map of all FFh, except for the first two bytes which are 

01xxh (xx is the Port’s AL_PA). The Port transmits the LIRP frame and waits to receive it back. 

g.   The AL_PA position map from the received LIRP is used to create a LILP frame. The Port transmits the LILP frame 

and waits to receive it back. 

h.   CLS is transmitted to put all other Ports into MONITORING state. When received back, the Loop Master itself goes 

to MONITORING state. 

4.   Non Loop Master 

LISM

1101 0000h

8 - byte Port_Name

LIFA

1102 0000h

16 - byte AL_PA bit map

LIPA

1103 0000h

16 - byte AL_PA bit map

LIHA

1104 0000h

16 - byte AL_PA bit map

LISA

1105 0000h

16 - byte AL_PA bit map

LIRP

1106 0000h

128 - byte AL_PA position map

LILP

1107 0000h

128 - byte AL_PA position map