The receiver receives 4-lane LAN WDM optical signals. The optical signals are de-multiplexed by a 1-to-4 optical DEMUX and each of the resulting 4 channels of optical signals is fed into one of the 4 receivers that are packaged into the Receiver Optical Sub-Assembly (ROSA). Each receiver converts the optical signal to an electrical signal. The regenerated electrical signals are retimed and de-jittered and amplified by the RX portion of the 4-channel CDR. The retimed 4-lane output electrical signals are compliant with IEEE CAUI-4 interface requirements. In addition, each received optical signal is monitored by the DOM section. The monitored value is reported through the MDIO section. If one or more received optical signal is weaker than the threshold level, RX_LOS hardware alarm will be triggered.
The CFP4 module supports the MDIO interface specified in IEEE802.3ba Clause 45. It supports alarm, control and monitor functions via hardware pins and via an MDIO bus. Upon module initialization, these functions are available. CFP4 MDIO electrical interface consists of 6 wires including 2 wires of MDC and MDIO, as well as 3 Port Address wires, and the Global Alarm wire. MDC is the MDIO Clock line driven by host and MDIO is the bidirectional data line driven by both host and module depending upon the data directions. The CFP4 uses pins in the electrical connector to instantiate the MDIO interface as listed in Table 1. MDIO Interface Pins.
