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ISL29011_14 Datasheet, PDF (9/19 Pages) Intersil Corporation – Digital Ambient Light Sensor and Proximity Sensor with Interrupt Function
ISL29011
I2C Interface
There are eight 8-bit registers available inside the ISL29011. The
two command registers define the operation of the device. The
command registers do not change until the registers are
overwritten. The two 8-bit data Read Only registers are for the ADC
output and the Timer output. The data registers contain the ADC's
latest digital output. The four 8-bit interrupt registers hold 16-bit
interrupt high and low thresholds.
The ISL29011’s I2C interface slave address is internally hard-wired
as 1000100. When 1000100x with x as R or W is sent after the
Start condition, this device compares the first seven bits of this byte
to its address and matches.
I2C DATA START
DEVICE ADDRESS W A REGISTER ADDRESS
Figure 3 shows a sample one-byte read. Figure 4 shows a sample
one-byte write. The I2C bus master always drives the SCL (clock) line,
while either the master or the slave can drive the SDA (data) line.
Figure 4 shows a sample write. Every I2C transaction begins with the
master asserting a start condition (SDA falling while SCL remains
high). The following byte is driven by the master, and includes the
slave address and read/write bit. The receiving device is responsible
for pulling SDA low during the acknowledgement period. Every I2C
transaction ends with the master asserting a stop condition (SDA
rising while SCL remains high).
For more information about the I2C standard, please consult the
Philips™ I2C specification documents.
STOP START DEVICE ADDRESS
A
DATA BYTE0
I2C SDA
IN
I2C SDA
OUT
A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A
SDA DRIVEN BY MASTER
A SDA DRIVEN BY MASTER A
A6 A5 A4 A3 A2 A1 A0 W A
SDA DRIVEN BY ISL29011
SDA DRIVEN BY MASTER
A D7 D6 D5 D4 D3 D2 D1 D0
I2C CLK
12 3456 789123456 789
123 45 67 89123456789
FIGURE 3. I2C READ TIMING DIAGRAM SAMPLE
I2C DATA
I2C SDA IN
I2C SDA OUT
I2C CLK IN
START
DEVICE ADDRESS
W A REGISTER ADDRESS
A
FUNCTIONS
A STOP
A6 A5 A4 A3 A2 A1 A0 W A R7 R6 R5 R4 R3 R2 R1 R0 A B7 B6 B5 B4 B3 B2 B1 B0 A
SDA DRIVEN BY MASTER
A
SDA DRIVEN BY MASTER
A
SDA DRIVEN BY MASTER
A
1 234 5 67 8 9 1234 56 7 8 9 12 345 67 89
FIGURE 4. I2C WRITE TIMING DIAGRAM SAMPLE
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9
FN6467.6
May 1, 2014