Finisar AN-2030 - Manual

AN-2030: Digital Diagnostic Monitoring Interface for Optical Transceivers
F i n i s a r
9/26/02 Revision D Page 1
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Application Note AN-2030
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Digital Diagnostic Monitoring Interface
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for SFP Optical Transceivers
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1. Scope and Overview
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This document defines an enhanced digital diagnostic monitoring interface available in 8
Finisar SFP and GBIC optical transceivers. The i nterface allows real time access to 9
device operating parameters, and it includes a sophisticated system of alarm and 10
warning flags which alerts end-users when particular operating parameters are outside 11
of a factory set normal range. The interface is fully compliant with SFF-8472, “Digital 12
Diagnostic Monitoring Interface for Optical Transceivers", revision 9.3. 13
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These digital diagnostic features are implemented in all Finisar SFP transceivers that 15
contain a “D” in the part number suffix (for example, FTRJ -1319-7D-2.5), as well as 16
DWDM and CWDM GBICs. All next generation Finisar SFPs utilizing the new part 17
numbering scheme (e.g. FTRJ1621P1BCL) also have the same diagnostic capability.
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The interface is an extension of the serial ID interface defined in the GBIC specification 20
as well as the SFP MSA. Both specifications define a 256-byte memory map in 21
EEPROM, which is accessible over a 2-wire serial interface at the 8 bit address 22
1010000X (A0h). The digital diagnostic monitoring interface makes use of the 8 bit 23
address 1010001X (A2h), so the originally defined serial ID memory map remains 24
unchanged. The interface is identical to, and is thus fully backward compatible with both 25
the GBIC Specification and the SFP Multi Source Agreement. The complete interface is 26
described in Section 3 below. 27
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The operating and diagnostics information is monitored and reported by a Digital 29
Diagnostics Transceiver Controller (DDTC), which is accessed via a 2-wire serial bus. 30
Its physical characteristics are defined in Section 4. 31
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2. Applicable Documents
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Gigabit Interface Converter (GBIC). SFF document number: SFF-0053, rev. 5.5, 37
September 27, 2000. 38
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Small Form Factor Pluggable (SFP) Transceiver MultiSource Agreement (MSA), 40
September 14, 2000. 41
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Digital Diagnostic Monitoring Interface for Optical Transceivers: SFF-8472, Draft 43
Revision 9.3, August 1, 2002. 44
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