Fujitsu MHV2120BH Manuel D’Utilisation

C141-E224 

6-11 

The host system can change the power consumption status of the interface by 
issuing the PARTIAL or SLUMBER request to the device. 

The interface power consumption states of this device can be separated into the 
following three modes, including the Active mode where the device is in the 
active state: 

• 

Active mode 

• 

Partial mode (shallow Interface Power Down) 

• 

Slumber mode (deep Interface Power Down) 

* 

The relationship of amount of power consumption in each mode is:  Active 
mode > Partial mode > Slumber mode.  The following table specifies a rule 
about the period in which the device must switch to Active mode from the 
Interface Power Down state: 

 

 

Period in which the device must switch to Active mode 

Partial mode 

Maximum 10 

µs 

Slumber mode 

Maximum 10 ms 

 

(1) Active mode 

The interface is in the Active state and commands can be accepted. 

(2) Partial mode 

In this mode, (shallow) Power Save mode is set for the interface circuit. 

The device switches to Partial mode when the following occurs: 

• 

The device receives the PMREQ_P signal from the host and responds with 

the PMACK signal 

• 

The device sends the PMREQ_S signal and the host responds with PMACK 

signal. 

The device cannot switch to Partial mode if the following condition is satisfied: 

• 

The device responds with the PMNAK signal because it is not waiting for 

commands. 

The device returns to Active mode from Partial mode when the following 
condition is satisfied: 

• 

The device receives the COMRESET or COMWAKE signal from the host.