user manual

1.3 Phy layer
C141-C013 37
Scenario 1: Both SAS phys start SAS OOB sequence at same time
A
B
Phy A Tx/
Phy B Rx
Phy A Rx/
Phy B Tx
COMINIT
COMSAS
COMINIT COMSAS
Time=0 Time=z
Scenario 2: SAS phy A starts SAS OOB sequence
A
B
Time=0 Time=z
COMINIT
COMINIT
COMSAS
COMSAS
Phy A Tx/
Phy B Rx
Phy A Rx/
Phy B Tx
Scenario 3: SAS phy B misses SAS phy A's COMINIT
COMINIT
COMSAS
B
A
Phy A Tx/
Phy B Rx
Phy A Rx/
Phy B Tx
Time=0
Time=z
COMINIT
COMSAS
A: SAS phy A power on
B: SAS phy B power on
Time 0 : SAS phy reset sequence begins
Time z : SAS speed negotiation sequence begins
Figure 1.10 SAS to SAS OOB sequence