Expander Communications Protocol Rev 1 is posted

John Lohmeyer lohmeyer at t10.org
Tue Aug 15 09:16:44 PDT 2000

* From the T10 Reflector (t10 at t10.org), posted by:
* John Lohmeyer <lohmeyer at t10.org>
I've posted rev 1 of my Expander Communications Protocol (ECP) to the T10 
ftp/web site:


Revision 1 changes:
1. Changed ECP protocol to be 8-bit asynchronous instead of 16-bit 
2. Changed the USED FLAG from one byte to one bit and renamed it USED.
3. Added an address assignment function and defined new direct addressing 
functions that work with
these addresses. This permits larger function structures and it allows 
functions to be sent to
expanders that currently do not have any targets addressable on the far port.
4. Added an enabling mechanism so that legacy initiators do not 
accidentally issue ECP functions.
Picked an eight-byte random number for the expander function signature.
5. Added an initiator data structure and a target data structure so that 
the same mechanism can be used
to set and report initiator, expander, and target margin settings.
6. Added capabilities to enable, disable, reset, and force single-ended 
mode on the far port.
7. Added ability to report the target port's bus mode.
8. Added support for the SCSI INQUIRY command to expanders, including 
relevant parts of the
standard INQUIRY data and VPD data.
9. Added rules for handling of reserved and unimplemented vendor-specific 
10. Removed the requirement to force bad parity on altered data if the 
incoming parity is bad.

John Lohmeyer                  Email: lohmeyer at t10.org
LSI Logic Corp.                Voice: +1-719-533-7560
4420 ArrowsWest Dr.              Fax: +1-719-533-7183
Colo Spgs, CO 80907

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