Fujitsu MAX3073NC - SCSI,80, Dell DC961,Hard Drive Scsi Logical Interface Specifications page 78

Command Specifications
Bit
Byte
0
1
2
3
4
5 PHSCRC
6
7
Figure 3.7
The operation mode parameter is configured from a 4-byte parameter list following a 4-byte header.
(1) Header
a) Bytes 0 to 2
X '00' must be specified in this field.
b) Parameter length
The parameter list length in byte 4 and subsequent bytes which follows the header must be specified
in this field. The parameter list length supported by the IDD is X '04' and the INIT must not specify
a value other than X '04' in this field. If a value other than X '04' is specified, this command is
terminated with a CHECK CONDITION status (ILLEGAL REQUEST [=5] / Invalid field in
parameter list [=26-00]) and the operation mode are not changed.
(2) Parameter list
a) WDTR (wide data transfer request: Effective for 16-bit SCSI devices only.)
This specifies whether or not a wide mode data transfer request from the IDD is permitted.
If this bit is set to 1, also set SDTR to 1. If only this bit is set but SDTR is not set, error code 5-26-00
is returned.
"1" (Permitted): After the power is switched on, after a RESET condition occurs or when the first
"0"* (Prohibited): If it is necessary to establish wide mode data transfer, the IDD does not send the
3-16
7 6 5
X'00'
X'00'
X'00'
X'04' (Parameter Length)
0 0 0
AGD ACE
X'xx' (Spindle Motor Start Delay Time)
X'00' (Reserved)
CHANGE DEFINITION command: operation mode parametor
command is received following reception of a BUS DEVICE RESET message, if a
WIDE DATA TRANSFER REQUEST (WDTR) message is not sent by the INIT, the
IDD sends the WDTR message and attempts to establish wide mode data transfer.
WDTR message. However, if the INIT sends the WDTR message, the IDD
responds normally.
* Set at shipping time
4 3 2
WDTR UNTAIN SDTR
0 0 0
1 0
Header
RSRTY 0
RTD
Parameter
List
C141-C010