CHAPTER 2 ACTIVE CABLING SPECIFICATIONS
SFP+ (Active Cable Specifications and Alternate Test Methods) Page
CHAPTER 2 ACTIVE CABLING SPECIFICATIONS
2.1 INTRODUCTION
High speed cabling specifications are based on SFI signalling as defined in SFF-8431 supporting either a limiting or linear host. Active cable assemblies may be used to provide operation over longer or thinner cables than achievable with direct attach copper assemblies. This section defines electrical specification and compliance testing methodology for such assemblies.
2.2 CABLE APPLICATIONS REFERENCE MODEL
A compliant active cable assembly is designated as 10GSFP+ACA and it can be identified by reading the memory map of SFF-8472.
The compliance points for SFP+ Active Cables(10GSFP+ACA) are the same as host compliance test points in 3.3.1 and the module compliance test points in 3.3.2 of SFF-8431.
All SFI test equipment must have 50 Ohms single ended impedance on all test ports.
Tx_Disable contacts in the module for cable assembly with active transmitter shall enable or disable the transmitter. For a passive assembly it shall be pulled to VccT with a 4.7 kΩ to 10 kΩ. The RX_LOS contact in the module for a cable assembly with active receiver shall be connected to the receiver IC loss of signal. A passive cable assembly RX_LOS contact shall be pulled low in the module. Direct connection of RX_LOS to VeeR is allowed for a cable assembly with passive receiver.
This specification does not assume transmit pre-emphasis beyond the level defined in SFF-8431.
Warning: 10GSFP+Cu can only be used on systems with common grounds. Connecting systems with different ground potential with SFP+ direct attach cable results in a short and may cause damage.
2.3 10GSFP+AC DIRECT ATTACH CONSTRUCTION
10GSFP+ACA SFP+ active cable assemblies could be copper or optical, providing either a linear or a limiting output. While particular implementations
