jsh-42l3ad3-5 JDS Uniphase Corporation, jsh-42l3ad3-5 Datasheet - Page 5

• Manufacturer Part Number: jsh-42l3ad3-5
• Description: Sfp Pluggable 4/2/1g Fc/gbe Fp And Dfb Transceiver Rohs 6/6 Jsh-42l3ad3-5, Jsh-42l3ad3-5g, Jsh-42l3ad3-20
• Manufacturer: JDS Uniphase Corporation

Two-wire Protocol for Serial ID and Digital Diagnostic Monitoring Information
Product specific information is stored in the device and is accessible via a standard two-wire interface. Some of the data is
non-volatile and some is updated real time with data that characterizes critical conditions of the transceiver. While most reg-
isters are read only, some registers can be written by the customer for use as scratch space or to set interrupt enables or clear
interrupt indicators.
There are two data addresses which can be used to access two different sets of data. The page address 0b1010000X is used for the
set of Serial ID data and the page address 0b1010001X is used for the set of Digital Diagnostic Monitoring information.
Critical timings for communicating to the module on the two-wire interface are shown in Two-Wire Interface Figure 8 on
page 8. For more information on the Serial ID protocol, see Two-Wire Interface Timing Specifications on page 14.
Two-wire Data Read
To read data from the device, the following sequence must occur on the Two-wire interface (refer to Two-Wire Interface Figure 2
on page 7, Two-Wire Interface Figure 3 on page 7, and Two-Wire Interface Figure 4 on page 7 throughout these steps):
1. To read data from the device, the following sequence must occur on the Two-wire interface (refer to Two-Wire Interface
2. Send a start signal to the module.
3. Receive an acknowledge signal.
4. Send the address of the first byte to be read during the subsequent sequence.
5. Receive an acknowledge signal.
6. Send a start signal.
7. Send the read data sequence.
8. Receive an acknowledge signal.
9. Receive a data byte.
10. Send an acknowledge signal to receive the next, consecutive data byte, or send a no-acknowledge signal followed by a stop
5
Figure 2 on page 7, Two-Wire Interface Figure 3 on page 7, and Two-Wire Interface Figure 4 on page 7 throughout these
steps):
A start signal is presented by toggling the data line from high to low while the clock is high (see Two-Wire Interface Figure
2 on page 7).
Send the write data sequence.
The write data sequence consists of the bits 0b10100000 for the Serial ID data or 0b10100010 for the Digital Diagnostic
Monitoring information.
One zero bit is the acknowledge signal.
Once this sequence has been acknowledged, the user will send the memory address to start reading from.
The read data sequence consists of the bits 0b10100001 for the Serial ID data or 0b10100011 for the Digital Diagnostic
Monitoring information.
Once this sequence has acknowledged, the user will begin receiving data bytes.
signal to stop receiving data.
A stop signal is presented by toggling the data line from low to high while the clock is high (see Two-Wire Interface Figure
2 on page 7).
SFP PlUGGABlE 4/2/1G FC/GBE FP AND DFB TRANSCEIvER ROHS 6/6