Fujitsu MBC2073RC Phy reset sequence after devices are attached, Phy reset sequence Example

SAS Interface

1.3.6.1Phy reset sequence after devices are attached

Since SAS signal cable connector does not include power lines, it is not possible to detect the physical insertion of the signal cable connector onto a plug. Non- cabled environments may similarly not have a way to detect physical insertion of a device. As a result, every time a phy reset sequence is originated:

Figure 1.14 shows how two phys complete the phy reset sequence if the phys are not attached at power on. In this example, phy A and phy B are attached some time before phy B's second hot-plug timeout occurs. Phy B's OOB detection circuitry detects a COMINIT after the attachment, and therefore phy B transmits COMSAS, since it has both transmitted and received a COMINIT. Upon receiving COMSAS, phy A transmits its own COMSAS. The SAS speed negotiation sequence follows.

COMINIT	Hot-Plug	COMINIT Hot-Plug	COMINIT	COMSAS
	Timeout	Timeout
Phy A Tx
A

Time=0 Time=y Time=z

Phy A Rx

B

Incomplete COMSAS

COMINIT

Phy B Tx

Phy B Rx

A

COMINIT Hot-PlugCOMINIT	COMSAS
Timeout
B

Time=0 Time=z

Time=y

COMINITCOMSAS

A:SAS phy A power on

B:SAS phy B power on

Time y : SAS phy A attached to SAS phy B

Time z: SAS phy A and SAS phy B start the SAS speed negotiation sequence

Figure 1.14 Phy reset sequence (Example)

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