FUJITSU C150-E049-02EN - Manual (Page 134)

M3099GX/GH OEM Manual 3-101
INTERFACE
A value of one in the first byte of a message indicates the beginning
of a multiple byte extended message. The minimum number of bytes
sent for an extended message is three. The extended message format
and the extended message code are shown in Table 3.84 and 3.85
respectively.
Table 3.84 Extended Message Format
Bit
Byte
0
1
2
3
n+1
7 6 5 3 2 1 0
Extended message (01h)
Extended message length (n)
Extended message code (y)
Extended message arguments
4
The extended message length specifies the length in bytes of the
extended message code plus the extended message arguments to
follow. Therefore, the total length of the message is equal to the
extended message length plus two. A value of zero for extended
message length indicates 256 bytes follow.
The extended message codes are listed in Table 3.85 The extended
message arguments are specified within the extended message
descriptions.
Table 3.85 Extended Message Codes
Code(s)
02h
00h
01h
03h
04h - 7Fh
80h - FFh
Description
Reserved (See Note)
MODIFY DATA POINTER
SYNCHRONOUS DATA TRANSFER REQUEST
WIDE DATA TRANSFER REQUEST
Reserved
Vendor Specific
Note: Extended message code 02h was used for the EXTENDED
IDENTIFY message in SCSI-1.
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