JSH-42L3AD3-20 JDS UNIPHASE, JSH-42L3AD3-20 Datasheet - Page 11

• Manufacturer Part Number: JSH-42L3AD3-20
• Manufacturer: JDS UNIPHASE

Specifications of JSH-42L3AD3-20

• Number Of Receivers: 1
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 3V
• Operating Temperature (max): 85C
• Lead Free Status / Rohs Status: Compliant

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 registers 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 Dig-
ital 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 14. For more information on the Serial ID protocol, see Two-Wire Interface Timing Specifi-
cations on page 23.
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 13, Two-Wire Interface Figure 3 on page 13, and Two-Wire Interface Figure
4 on page 13 throughout these steps):
10. Send an acknowledge signal to receive the next, consecutive data byte, or send a no-acknowledge signal
October 2008
1. Send a start signal to the module.
2. Send the write data sequence.
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.
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 13).
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.
followed by a stop 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 13).
JSH-42L3AD3-20S / 64P0682
JDSU Product Specification 21121822-001
LW 4x/2x/1x FC SFP with DDM
Page 11 of 45
,