Fujitsu MHW2120BJ User Manual

When the disk drive is waiting for commands, it can enter one of three IPM modes 
as requested by the host.  The three IPM modes are: 

1)  Partial mode: 

PMREQ_P is sent when the host requests the Partial mode. 

2)  Slumber mode:  PMREQ_S is sent when the host requests the Slumber mode. 

3)  Active mode: 

When the serial ATA interface is in active state. 

There are three interface (I/F) power states:  Active, Partial, and Slumber.  As 
requested by the host, the disk drive switches its I/F power state from the Active 
state to the Partial state, or from the Active state to the Slumber state. 

If this function is enabled by Set Features command, the disk drive shifts to two 
kinds of IPM modes automatically under the Idle condition. 

1)  Partial mode: 

PMREQ_P is sent when the disk drive requests the Partial 

mode. 

2)  Slumber mode:  PMREQ_S is sent when the disk drive requests the Slumber 

mode. 

I/F power states 

1) Active 

state 

The SATA interface is active, and data can be sent and received. 

2) Partial 

state 

The SATA interface is in the Power Down state.  In this state, the interface is 
switched to the Partial state when a PMREQ_P signal is received from or sent 
to host.  Because the return time to the Active state from the Partial state is 
specified as within 10 

µs, the degree of the I/F Power Save mode is shallow 

so that this recovery time is satisfied. 

3) Slumber 

state 

The SATA interface is in the Power Down state.  In this state, the interface is 
switched to the Slumber state when a PMREQ_S signal is received from or 
sent to host.  Because the return time to the Active state from the Slumber 
state is specified as within 10 ms, the degree of the I/F Power Save mode is 
deep so that this recovery time is satisfied. 

C141-E259 

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