Seagate Cheetah ST173404FC, Product Manual

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Cheetah 73FC Product Manual, Rev. C 55
9.5.11.1 Parallel 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.
9.5.12 Device control codes
The drive inputs a Device Control Code on the DEV_CTRL_CODE lines at power up to determine the link rate
on the Fibre Channel ports. Both ports run at the same rate. If the backpanel does not connect to these lines,
the drive has 10K ohm pull up resistors that default the device control code to 7 (1.0625 GHz). Table 22 lists the
supported codes.
Table 22: Device control code values
2 (pin 17) 1 (pin 18) 0 (pin 39) Definition
0 0 0 Power failure warning.
0 0 1 Reserved for auto negotiation of link rate.
0
1
0 Reserved.
0 1 1 Reserved.
1 0 0 Reserved.
1
0
1 Reserved.
1 1 0 2.125 GHz operation on both ports.
1 1 1 1.0625 GHz operation on both ports.