x9520v20iz-bt1 Intersil Corporation, x9520v20iz-bt1 Datasheet - Page 4

• Manufacturer Part Number: x9520v20iz-bt1
• Description: Fiber Channel/gigabit Ethernet Laser Diode Control For Fiber Optic Modules Triple Dcp, Por, 2kbit Eeprom Memory, Dual Voltage Monitors
• Manufacturer: Intersil Corporation

Pin Descriptions
Principles of Operation
Serial Interface
SERIAL INTERFACE CONVENTIONS
The device supports a bidirectional bus oriented protocol.
The protocol defines any device that sends data onto the
bus as a transmitter, and the receiving device as the
receiver. The device controlling the transfer is called the
master and the device being controlled is called the slave.
The master always initiates data transfers, and provides the
clock for both transmit and receive operations. Therefore,
the X9520 operates as a slave in all applications.
SERIAL CLOCK AND DATA
Data states on the SDA line can change only while SCL is
LOW. SDA state changes while SCL is HIGH are reserved
for indicating START and STOP conditions. See Figure 1.
On power-up of the X9520, the SDA pin is in the input mode.
SERIAL START CONDITION
All commands are preceded by the START condition, which
is a HIGH to LOW transition of SDA while SCL is HIGH. The
device continuously monitors the SDA and SCL lines for the
TSSOP
19
20
V1/VCC Supply Voltage.
NAME
V1RO
SCL
SDA
SCL
SDA
V1/VCC RESET Output. This is an active HIGH, open drain output which becomes active whenever V1/VCC falls below
V
be changed by varying the POR0 and POR1 bits of the internal control register). The V1RO pin requires the use of an external
“pull-up” resistor. The V1RO pin can be forced active (HIGH) using the manual reset (MR) input pin.
TRIP1
(Continued)
. V1RO becomes active on power-up and remains active for a time t
4
FIGURE 2. VALID START AND STOP CONDITIONS
DATA STABLE
START
FIGURE 1. VALID DATA CHANGES ON THE SDA BUS
X9520
DATA CHANGE
FUNCTION
START condition and does not respond to any command
until this condition has been met. See Figure 2.
SERIAL STOP CONDITION
All communications must be terminated by a STOP condition,
which is a LOW to HIGH transition of SDA while SCL is HIGH.
The STOP condition is also used to place the device into the
Standby power mode after a read sequence. A STOP
condition can only be issued after the transmitting device has
released the bus. See Figure 2.
DATA STABLE
STOP
purst
after the power supply stabilizes (t
August 20, 2007
purst
FN8206.2
can