Seagate 2250 Computer Drive User Manual


 
When the standby timer expires, the drive makes the transition to the
Standby mode. The drive requires approximately 100–200 msec to return
to Active mode from Idle mode.
Standby mode.
The drive enters Standby mode when the host sends a
Standby or Standby Immediate command. If the standby command has set
the standby timer, the drive enters Standby mode automatically after the
drive has been inactive for the specified length of time. In Standby mode,
the buffer remains enabled, the heads are parked and the spindle is at rest.
The drive accepts all commands and returns to Active mode any time a disc
access command is received. The drive requires approximately 3 seconds
to return to Active mode from Standby mode.
Sleep mode.
The drive enters Sleep mode only after receiving a Sleep
command from the host. The heads are parked and the spindle is at rest.
The ROM and RAM codes are valid; however, the cache is flushed before
going to sleep. The drive leaves Sleep mode when either a Hard Reset
interface signal or a Soft Reset signal (Device Control register=04) is
received from the host. After receiving a Soft Reset, the drive exits Sleep
mode and enters Standby mode, with all current emulation and transla-
tion parameters intact. After receiving a Hard Reset signal, the drive exits
Sleep mode and enters Active mode. The drive is reinitialized to the
default parameters. This is the same procedure as initial power-on and
requires approximately 7 seconds to complete.
Idle and standby timers.
The drive sets the default time delay for the idle
timer at power-on to 5 seconds. If the idle timer reaches zero before any
drive activity is required, the drive makes a transition to Idle mode. Each
time the drive performs an Active function (read, write or seek), the idle and
standby timers are reinitialized and begin counting down from their specified
delay times to zero. If the standby timer has been set and no additional drive
activity occurs, the drive remains in Idle mode for the time specified in the
standby timer, then enters Standby mode.
If the host has not set the standby timer and no additional drive activity
occurs, the drive remains in Idle mode for 30 minutes, then enters standby
mode. In both Idle and Standby mode, the drive accepts all commands and
returns to Active mode when disc access is necessary.
Marathon 2250 and Marathon 1680 Product Manual 11