Fujitsu MBC2073RC Manual Do Utilizador

36 

C141-C013 

 

Figure 1.9 describes SAS OOB signal detection by the SP receiver. 

 

 

1

 

2

 

3

 

4

 

n

 

n

 

1

 

2

 

3

 

4

 

n

 

Any transitions

 

COMINIT 
detected 

COMRESET/COMINIT 

COMINIT 
negation

 

COMSAS 

Any transitions

 

idle

 

ALIGN burst

 

nth 
idle/Burst pair 

idle/Burst pair

 

COMSAS 
detected 

COMSAS 

negation 

 

During the OOB sequence, the INIT and the drive first send the COMINIT signal 
to each other, then the COMSAS signal.  When they both have received the 
COMSAS signal from each other, the OOB sequence is recognized as having been 
performed successfully.  Depending on the power-on timing, reception of the 
COMINIT signal from the other side may not be detected.  In such a case, 
however, the OOB sequence is recognized as having been performed successfully 
if the COMINIT and COMSAS signals have been sent by the time the COMSAS 
signal from the other side is received. 

When the OOB sequence is successful, the SAS speed negotiation sequence starts. 

Figure 1.10 shows several different SAS OOB sequences between phy A and phy 
B, with phy A starting the SAS OOB sequence at the same time as phy B, before 
phy B, and before phy B powers on.