Comments concerning spi4r07, Annex G: "Expander Communication Protocol"
gromo at qlogic.com
Tue Oct 9 16:04:35 PDT 2001
* From the T10 Reflector (t10 at t10.org), posted by:
* Gil Romo <gromo at qlogic.com>
To whom it may concern,
Please accept the following comments for review.
Paragraph 4 of G.5 "Communicative expander function structures" states incorrect
data structure size of multiple function data buffer. The correct size is 176
(16-byte header plus ten 16-byte SEDB = 11*16 = 176).
Paragraph 1 of G.6.2.2 "CONTROL" identifies the data structure shown in Table
G.7 "CONTROL data structure" as a SEDB (short expander descriptor block).
However, since CONTROL is a single function, its data buffer should be a LEDB
(long expander descriptor block).
No single function should require a USED bit, since each provides an EXPANDER
ADDRESS in the data buffer and the INITIATOR ADDRESS in the function header
(G.6.2 "Outbound single functions" and G.6.4 "Inbound single functions").
G.5 "Communicative expander function structures" states that, for outbound
functions, the MODE field of the WRITE BUFFER command shall be set to write
data, echo buffer or echo buffer plus enable ECP mode, and for inbound
functions, the MODE field of the READ BUFFER command shall be set to write data,
echo buffer or echo buffer plus enable ECP mode. However, G.6.1.1, G.6.2.1,
G.6.3.1 and G.6.4.1 specify " a WRITE BUFFER command with the MODE field set to
one of the values specified in table G.2" ("Expander functions"). The latter
statement should be corrected by referencing the expander function code field of
the expander function header ("Table G.1").
(949) 389 - 6266
Gil.Romo at Qlogic.com
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