Hitachi HUS154530VLF400 User Manual

Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification

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* level of backplane support as established in 'discovery'
** the direction is determined by the state of DSK_RD and DSK_WR
all signals are assumed valid 1 usec after -Parallel ESI changes state

The SFF-8045 Enclosure Service Interface defines 7 bits of enclosure status. This status is read by the drive, and presented to 
the initiator, upon receipt of the appropriate SCSI RECEIVE DIAGNOSTIC command. The definitions of the status bits are 
vendor specific. The drive does not try to interpret the status. The drive assumes -EFW is status and treats it as it does the other 
P_ESI_n signals.

The SFF-8067 Enclosure Service Interface defines a bidirectional communication path between the backplane and the drive. 
Read Communications are invoked by the drive upon receipt of the appropriate SCSI RECEIVE DIAGNOSTIC command. 
This has the system level effect of the host reading information from the enclosure. Write Communications are invoked by the 
drive upon receipt of the appropriate SCSI SEND DIAGNOSTIC command. This has the system level effect of the host writ-
ing information to the enclosure. The meaning of the information is vendor specific. The drive does not try to interpret the 
information. See the SFF-8067 Specification for a detailed description of the communication protocol.

7.1.7   –ENBL_BYP CH1, -ENBL_BYP_CH2

These TTL outputs from the drive provide 4mA of sink capability. They are intended to control the state of a loop port bypass 
circuit on the backplane. The drive powers up with these signals turned off. It is assumed that the backplane will provide a 
1Kohm pull-down resistor that will ensure the drive is bypassed on the loop when it is not present, or when it is powering up. 
After a successful power-up, the drive will attempt to enable itself on both loops (if allowed to do so via SCSI mode page 19h). 
These signals are also controllable by the host with the LPB and LPE fibre channel primitives.

7.1.8   –Drive Present

This signal is connected to the drive's ground plane. The backplane can use this signal to detect the presence of the drive.

The signals DEV_CTRL_CODE_2 through DEV_CTRL_CODE_0 provide a binary code to the drive to control functions 
such as FC link rate, Power Failure Warning (PFW) and Hard Reset. The control function is either identified by a code or a 
sequence of codes on the DEV_CTRL_CODE signals. The table below defines the functions and assigned codes that use a 

de-asserted (high)

SFF-8045*

SFF-8067*

Sel_0 (input)

P_ESI_0 (input)

Data(0) (bi-di**)

Sel_1 (input)

P_ESI_1 (input)

Data(1) (bi-di**)

Sel_2 (input)

P_ESI_2 (input)

Data(2) (bi-di**)

Sel_3 (input)

P_ESI_3 (input)

Data(3) (bi-di**)

Sel_4 (input)

P_ESI_4 (input)

-ENCL_ACK (output)

Sel_5 (input)

P_ESI_5 (input)

-DSK_RD (input)

Sel_6 (input)

-EFW (input)

-DSK_WR (input)