Seagate ST34321A Product Manual - Page 19

Medalist 8641, 6531, 4321, 3221 and 2110, Rev. B 11 1.7.4 Power-management modes These drives provide programmable power management to provide greater energy efficiency. In most systems, you can control power management through the system setup program. These Seagate drives feature several power-management modes, which are summarized in the following table and described in more detail below: Mode Active Idle Standby Sleep Heads Tracking Tracking Parked Parked Spindle Rotating Rotating Stopped Stopped Buffer Enabled Enabled Enabled Disabled Active mode. The drive is in Active mode during the read/write and seek operations. Idle mode. The buffer remains enabled, and the drive accepts all commands and returns to Active mode any time disc access is necessary. Standby mode. The drive enters Standby mode when the host sends a Standby Immediate command. If the host has set the standby timer, the drive can also enter Standby mode automatically after the drive has been inactive for a specifiable length of time. The standby timer delay is established using a Standby or Idle command. In Standby mode, the heads are parked and the spindle is at rest. The drive accepts all commands and returns to Active mode any time disc access is necessary. Sleep mode. The drive enters Sleep mode after receiving a Sleep command from the host. The heads are parked and the spindle is at rest. The drive leaves Sleep mode after it receives a Hard Reset or Soft Reset from the host. After receiving a reset, the drive exits Sleep mode and enters Active mode with all current translation parameters intact. Standby timers. Each time the drive performs an Active function (read, write or seek), the standby timer is reinitialized and begins counting down from its specified delay times to zero. If the standby timer reaches zero before any drive activity is required, the drive makes a transition to Standby mode. In both Idle and Standby mode, the drive accepts all commands and returns to Active mode when disc access is necessary.