Clarification on 8 byte single level LUN format in SPI-4

George Penokie gop at us.ibm.com
Tue Aug 27 12:10:24 PDT 2002


* From the T10 Reflector (t10 at t10.org), posted by:
* George Penokie <gop at us.ibm.com>
*




Guy,

The MSB list in the LUN field in the L_Q IU in SPI-4 is byte zero in Table
1 (Single Level LUN structure) in SAM-2. So byte 0 (00h) in the single
level LUN structure (table 1 in SAM-2) would be placed into the byte 4 in
the SPI L_Q information unit (table 54 in SPI-4). Byte 1(the single level
LUN value) would be in byte 5, byte 2 (00h) would be in byte 6, etc.

Transmission order, from the SCSI point of view,  is always MSB to LSB (i.
e, byte 0 to byte n).

Bye for now,
George Penokie

Dept 2C6  114-2 N212
E-Mail:    gop at us.ibm.com
Internal:  553-5208
External: 507-253-5208   FAX: 507-253-2880




                                                                                                                                       
                      "Kendall, Guy"                                                                                                   
                      <gkendall at lsil.          To:       "'t10 at t10.org'" <t10 at t10.org>                                                 
                      com>                     cc:       "Perucca, Nick" <Nick.Perucca at lsil.com>                                       
                      Sent by: owner-          Subject:  Clarification on 8 byte single level LUN format in SPI-4                      
                      t10 at t10.org                                                                                                      
                                                                                                                                       
                                                                                                                                       
                      08/27/02 12:08 PM                                                                                                
                                                                                                                                       
                                                                                                                                       



* From the T10 Reflector (t10 at t10.org), posted by:
* "Kendall, Guy" <gkendall at lsil.com>
*
The SPI-4 L_Q contains an 8 byte LUN field where the MSB is sent first, and
the LSB sent last. SPI-4 references SAM-2 for the format of the 8 bytes. In
SAM-2 rev. 23, section 4.8, table 1 shows the format of the Single Level
LUN
structure. Byte one shall contain the 8-bit LUN, and all other bytes shall
be zero.

I am looking for 100% clarification on which bytes in the SPI-4 table match
up with the SAM-2 table. I thought I understood this, but now it is in
question and I'm looking for clarification.

My question is, in the SPI-4 L_Q, does the MSB correspond to byte zero in
the Single Level LUN format in SAM-2, or to byte 7? Since the actual 8-bit
LUN is in byte one of the single level LUN structure, will this LUN byte be
sent out second or seventh of the 8 bytes?

Thanks,
Guy Kendall

*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at t10.org



*
* For T10 Reflector information, send a message with
* 'info t10' (no quotes) in the message body to majordomo at t10.org




More information about the T10 mailing list