Finisar AN-2030 specifications Vendor Rev, Laser Wavelength, Dwdm Wavelength Fraction

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AN-2030: Digital Diagnostic Monitoring Interface for Optical Transceivers

F i n i s a r

1Vendor Rev

2 The vendor revision number (vendor rev) is a 4-byte field that contains ASCII

3characters, left-aligned and padded on the right with ASCII spaces (20h), defining the

4vendor’s product revision number. A value of all zero in the 4-byte field indicates that

5the vendor rev is unspecified. All legacy Finisar transceivers contain zero in all 4 bytes

6or ASCII space (20h) in all four bytes or one of two place holders: “X1—“ or “1A—“.

7Early versions of the digital diagnostic standard (SFF-8472), used a scale factor of

81µA/AD Count for interpreting laser bias current readings. SFF-8472 later changed the

9scale factor to 2µA/AD Count. All Finisar modules using a scale factor of 2µA/AD Count

10have an ASCII “A” written in byte 56 of this field.

11

12Laser Wavelength

13Nominal transmitter output wavelength at room temperature. This field is a 16 bit value

14with byte 60 as high order byte and byte 61 as low order byte. The laser wavelength is

15equal to the the 16 bit integer value in nm. This field allows the user to read the laser

16wavelength directly, so it is not necessary to infer it from the transceiver “Code for

17Electronic Compatibility” (bytes 3 – 10). This also allows specification of wavelengths

18not covered in bytes 3 – 10, such as those used in coarse WDM systems.

19

20DWDM Wavelength Fraction

21Byte 62 is reserved (set to 00h) in the SFP MSA as well as SFF-8472. Finisar DWDM

22transceivers use this byte in conjunction with bytes 60-61 to indicate the DWDM

23transceiver laser wavelength. Bytes 60-61 provide the integer wavelength in units of

24nm. In DWDM transceivers, by 62 provides the fractional wavelength in units of

250.01nm. Thus the wavelength for a particular DWDM transceiver is given by:

26(byte 60,61) + (byte 62 * 0.01nm). In all non-DWDM Finisar transceivers, this byte is set

27to 00h.

28

29CC_BASE

30The check code is a one byte code that can be used to verify that the first 64 bytes of

31serial information in the SFP is valid. The check code shall be the low order 8 bits of the

32sum of the contents of all the bytes from byte 0 to byte 62, inclusive.

33

34

9/26/02 Revision D

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Contents 35 2. Applicable Documents Scope and OverviewEnhanced Digital Diagnostic Interface Definition Overview Control Functions 8 bytes Password Entry 8 bytesSpecific Data Field Descriptions Cal Constants BytesName Bytes Description of Field Address Serial ID Data Fields Address A0Data Extended Identifier ConnectorIdentifier Identifier valuesDescription of connector Connector valuesTransceiver codes TransceiverCode Description of encoding mechanism 4a Sonet Reach SpecifiersEncoding Speed Reach Specifier bit DescriptionLength 50μ BR, nominalLength 9μ-km Length 9μVendor OUI Length CopperVendor name Dwdm Channel SpacingDwdm Wavelength Fraction Vendor RevLaser Wavelength 13 BR, min OptionsOption values BR, maxData Description of field Address Diagnostic Monitoring TypeDate Code N i s a r Enhanced Options 11 SFF-8472 Compliance 10 I/O Timing for Soft Control & Status FunctionsSFF-8472 Compliance Diagnostics 13 Digital temperature format Temperature 12 Bit weights C for temperature reporting registersN i s a r 14 Alarm and Warning Thresholds 2-Wire Address A2h Alarm and Warning ThresholdsN i s a r 16b Format for offsets 16a Unsigned fixed-point binary format for slopes16d Example of Floating Point Representation 16c IEEE-754 Single-Precision Floating Point Number FormatBit Name Description LOS Alarm and Warning Flags18 Alarm and Warning Flag Bits 2-Wire Address A2h Address # Bytes Name Description 19 Password Addresses 2-Wire Address A2h20 User Eeprom 2-Wire Address A2h Byte Bit Name DescriptionDdtc Electrical Interface Definition Overview Wire Interface OperationN i s a r Current Address Read Detailed 2 -Wire Serial Port Operation N i s a r Wire Protocol Data Transfer Protocol Vcc = 3.15V to DC Electrical CharacteristicsFor More Information
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