SAS 아키텍쳐

SAS 아키텍쳐

Physical layer:

• 전기의 정의와 물리적 특성
• 차별적인differential 신호 전달
• 3개의 연결 타입 :
  • SFF 8482 – SATA 호환
  • SFF 8484 – up to 네개 디바이스
  • SFF 8470 – 외부 커넥터 (InfiniBand 커넥터), up to four devices

PHY Layer:

• 8b/10b 데이터 인코딩
• Link initialization, speed negotiation and reset sequences
• Link capabilities negotiation (SAS-2)

Link layer:

• clock-speed 불균형 매칭의추가 그리고 삭제
• Primitive encoding
• Data scrambling for reduced EMI
• Establish and tear down native connections between SAS targets and initiators
• Establish and tear down tunneled connections between SAS initiators and SATA targets connected to SAS expanders
• Power management (proposed for SAS-2.1)

Port layer:

• Combining multiple PHYs with the same addresses into wide ports

Transport layer:

• Supports three transport protocols:
  • Serial SCSI Protocol (SSP): supports SAS devices
  • Serial ATA Tunneled Protocol (STP): supports SATA devices attached to SAS expanders
  • Serial Management Protocol (SMP): provides for the configuration of SAS expanders

Application layer