IGP-28111J Datasheet, PDF (12/17 Pages) Bookham, Inc. – SFP Optical Transceivers for 2.7Gb/s 180km DWDM Applications

Data Sheet
Diagnostics specifications
A digital diagnostics interface is available on Bookham SFP
transceivers as a 2-wire serial interface and provides user
access to module identification data, customer specific data,
link type, static and dynamic monitors and a check code
mechanism for verifying accuracy in the data registers. These
static and dynamic diagnostics allow users to remotely and
accurately identify modules and their vendors, enquire about
its compatibility with the system and also verify which
enhanced diagnostics are supported. The user can also
monitor module parameters to determine the module and link
condition and provide hardware alerts upon an alarm or
warning event.
The Enhanced Digital Diagnostics provide real-time monitoring
of receiver input power, transmitter power,
internal module temperature, laser bias current and supply
voltage parameters.
The 2-wire serial interface is defined by the GBIC (GigaBit
Interface Converter) specification and the SFP MSA
(Multi-Source Agreement) document dated September 14th,
2000. It is also compliant with the proposed DWDM SFP MSA
Document. This interface allows read-only access to two
separate memory locations starting at 1010000X (A0h)
and 101000X (A2h). Table 3 and Table 4 contain address
descriptions and register mapping information for both
memory locations.
The memory location starting at A0h (data address 0 ~ 128)
contains the Serial ID fields. This is a static data memory
location for details such as vendor information, module
identification, user specific data and a check code for verifying
accuracy in the data registers.
The memory location starting at A2h (data address 0 ~ 255)
contains Enhanced Diagnostics fields. The Enhanced
Diagnostics are based on the SFF-8472 specification
developed in the SFF (Small Form Factor) standards
organization with an added TX_FAULT interrupt feature that
provides a hardware alert upon reaching an alarm or warning
condition on any, or all, of the diagnostics monitors. Enhanced
Diagnostics provide a real-time indication of system and
module condition, alerting the user to apparent or pending link
or module problems. This is implemented through the use of
alarm and warning registers that are updated approximately
every 60 milliseconds. Data from these registers are internally
calibrated over the specified operating ranges as described in
this data sheet. Alarm and warning thresholds are factory
preset values and are interpreted as real 16 bit data. The
optional TX_FAULT interrupt feature, if activated, pulls the
TX_FAULT pin (pin 2) high upon reaching an alarm or warning
condition on the diagnostics monitors mentioned above. The
masking feature allows any of the warning and alarm flags to
be dynamically masked by the user.
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