Seagate ST336807FC manual Motor start controls, Motor start control signals

9.5.10Motor start controls

The drive’s motor is started according to the Start_1 and Start_2 signals described in Table 30. The state of these signals can be wired into the backplane socket or driven by logic on the backplane.

Table 30:	Motor start control signals
Case	Start_2	Start_1	Motor spin function
1	Low	Low	Motor spins up at DC power on.
2	High	Low	Motor spins up only when SCSI Start command is received.
3	Low	High	Motor spins up after a delay of 12 seconds times the modulo 8 value of
			the numeric SEL ID of the drive from DC power on.
4	High	High	The drive will not spin up.

9.5.11SEL_6 through SEL_0 ID lines

The SEL_6 through SEL_0 ID lines determine drive address, and, optionally, for an Enclosure Services Inter- face. When the Parallel ESI line is high, the enclosure backpanel must provide address information on the SEL line. Refer to table 31 for a mapping of SEL to FC-AL physical addresses (AL_PA). You can think of the SEL lines as the equivalent of a backpanel logic plug. The drives does not provide pull up resistors on these lines. The backpanel is required to provide high and low inputs to the SEL_ID lines per the specifications in table 33 on page 67.

Note. Table 31 gives AL_PA values for each SEL value. The first entry in the table is SEL_ID 00. The last entry is SEL_ID 7D. SEL_ID 7E is AL_PA 00 which is not valid for an NL_Port, so is not included in the table. Also, SEL_ID 7Fh does map to a valid AL_PA; however, this value signals the drive that physical addresses are not being assigned using the SEL lines and that a “soft” address will be determined by FC-AL loop initialization.

When the Parallel ESI line is low, the enclosure backpanel logic switches to ESI mode if supported. There are two modes of ESI, seven bits of enclosure status and a bidirectional mode. ESI support and the mode are determined by the drive using a discovery process. Refer to the Fibre Channel Interface Manual for a descrip- tion of ESI operation.

9.5.11.1Parallel Enclosure Services Interface (ESI)

The parallel ESI line is an output from the drive. This line provides the enclosure with an indication of the present function of the SEL lines. A high level, the default state, indicates the drive requires address informa- tion on the SEL lines. A low level indicates the drive is attempting an ESI transfer. The enclosure may not sup- port ESI on any or all drive locations. It may only support the address function. Support of ESI is discovered by the drive. Refer to the Fibre Channel Interface Manual for a description of ESI operations.

Cheetah 10K.7 36GB FC Product Manual, Rev. A 65