Seagate ST318418N, ST318438LW manual Drive activity LED, Barracuda 36ES2 Product Manual, Rev. B

74		Barracuda 36ES2 Product Manual, Rev. B
Table 17: Disc drive SCSI timing (Continued)
	Waveform		Waveform
Description	symbol [1]		table [1]	Typical timing
Data In Byte Transfer (parameter)	T24		4.5-12	0.04 ∝s
Data Out Byte Transfer (parameter)	T25		4.5-13	0.04 ∝s
Next Data In Byte Access (parameter)	T26		4.5-12	0.12 ∝s
Next Data Out Byte Access (parameter)	T27		4.5-13	0.12 ∝s
Data In Byte Transfer (media) [2]	T28		4.5-12	0.04 ∝s
Data Out Byte Transfer (media) [2]	T29		4.5-13	0.04 ∝s
Next Data In Byte access (media [2]	T30		4.5-12	0.12 ∝s
Next Data Out Byte access (media [2]	T31		4.5-13	0.12 ∝s
MSG IN Byte Transfer	T32		4.5-5,7,8,14,15	0.04 ∝s
MSG OUT Byte Transfer	T33		4.5-2	0.04 ∝s
STATUS Byte Transfer	T34		4.5-5,8,15	0.04 ∝s
Synchronous Data Transfer Characteristics:
Request Signal Transfer Period [3]	–		–	various (800 ns max)

Notes.

[1]See the SCSI Interface Product Manual, part number 75789509, timing examples section.

[2]Maximum SCSI asynchronous interface transfer rate is given in Section 4.2.3 of this manual.

[3]Synchronous Transfer Period is determined by negotiations between an Initiator and a Drive. The Drive is capable of setting periods as given in Section 9.5. See also the Synchronous data transfer section and the Extended messages section of the SCSI Interface Product Manual, for a description of synchronous data transfer operation.

9.11Drive activity LED

The following table provides drive activity LED status.

Table 18: Drive activity LED status

Spindle status	Command status	LED status
Spinning up with DC power applied	N/A	On until spinup is complete
Spun down	Start Unit	On while processing the command
Powered down by removal of DC power	N/A	Off due to absence of power
Spun up	Stop Unit	On while processing the command
Spun down	No command activity	Off
Spun down	Write/Read Buffer	On while processing the command
Spun down	SCSI Bus Reset	On while processing the reset
Spun down	Test Unit Ready	On while processing the command
Spun up	No command activity	Off
Spun up	Write/Read	On while processing the command
Spun up	SCSI Bus Reset	On while processing the reset
Spun up	Test Unit Ready	On while processing the command
Spun up	Format with Immediate option on	On while the command is initially processed
Spun up	Format without Immediate	LED toggles on/off on each cylinder boundary