SATA

SerialATA_Revision_3_1_Gold.pdf

SAS

4 layer

Application， Transport, Link , PHY 应用层，传输层，链路层，物理层，

Hardware control

• DSS (Disable staggered spin-up) //硬盘交错启动，避免启动大电流
• DAS (Device activity signal)(led)
• DHU (Direct Head Unload)

eSTAT 硬盘盒场景，在controller和HDD中间多了一个IC芯片

Hot Plug

Precharge

PHY layer

• NRZ
• 100ohm differential termination
• Encoding&Decoding#8B/10B(comma in block)

GND 先接触

Hot Plug