Finisar FTLX1471D3BCL Modules 10G Transceiver 10Km 1310nm SFP Fiber

Digital Diagnostic Functions

Finisar FTLX1471D3BCL SFP+ transceivers support the 2-wire serial communication protocol as defined in the SFP MSA1 . It

is very closely related to the E2 PROM defined in the GBIC standard, with the same electrical specifications. The standard SFP

serial ID provides access to identification information that describes the transceiver’s capabilities, standard interfaces,

manufacturer, and other information. Additionally, Finisar SFP+ transceivers provide a enhanced digital diagnostic monitoring

interface, which allows real-time access to device operating parameters such as transceiver temperature, laser bias current,

transmitted optical power, received optical power and transceiver supply voltage. It also defines a sophisticated system of alarm

and warning flags, which alerts end-users when particular operating parameters are outside of a factory set normal range. The

SFP MSA defines a 256-byte memory map in E2 PROM that is accessible over a 2-wire serial interface at the 8 bit address

1010000X (A0h). The digital diagnostic monitoring interface makes use of the 8 bit address 1010001X (A2h), so the originally

defined serial ID memory map remains unchanged. The interface is identical to, and is thus fully backward compatible with both

the GBIC Specification and the SFP Multi Source Agreement. The complete interface is described in Finisar Application Note

AN2030: “Digital Diagnostics Monitoring Interface for SFP Optical Transceivers”. The operating and diagnostics information is

monitored and reported by a Digital Diagnostics Transceiver Controller (DDTC) inside the transceiver, which is accessed

through a 2-wire serial interface. When the serial protocol is activated, the serial clock signal (SCL, Mod Def 1) is generated by

the host. The positive edge clocks data into the SFP transceiver into those segments of the E2 PROM that are not write-

protected. The negative edge clocks data from the SFP transceiver. The serial data signal (SDA, Mod Def 2) is bi-directional for

serial data transfer. The host uses SDA in conjunction with SCL to mark the start and end of serial protocol activation. The

memories are organized as a series of 8-bit data words that can be addressed individually or sequentially. For more

information, please see the SFP MSA documentation1,5 and Finisar Application Note AN-2030. Please note that evaluation

board FDB-1018 is available with Finisar ModDEMO software that allows simple to use communication over the 2-wire serial

interface