TCS3771 Datasheet, PDF (16/33 Pages) ams AG – COLOR LIGHT-TO-DIGITAL CONVERTER with PROXIMITY SENSING

TCS3771
COLOR LIGHT-TO-DIGITAL CONVERTER
with PROXIMITY SENSING
TAOS110A − MARCH 2011
I²C Protocol
Interface and control are accomplished through an I²C serial compatible interface (standard or fast mode) to
a set of registers that provide access to device control functions and output data. The devices support the 7-bit
I²C addressing protocol.
The I²C standard provides for three types of bus transaction: read, write, and a combined protocol (Figure 15).
During a write operation, the first byte written is a command byte followed by data. In a combined protocol, the
A
N
P
R
S
Sr
W
...
1
S
first byte written is the command byte followed by reading a series of bytes. If a read command is issued, the
register address from the previous command will be used for data access. Likewise, if the MSB of the command
is not set, the device will write a series of bytes at the address stored in the last valid command with a register
lid ^{address. The command byte contains either control information or a 5-bit register address. The control}
commands can also be used to clear interrupts.
The I²C bus protocol was developed by Philips (now NXP). For a complete description of the I²C protocol, please
a _{review the NXP I}²_{C design specification at http://www.i2c−bus.org/references/.}
v _{Acknowledge (0)}
Not Acknowledged (1)
ill ^{Stop Condition}
Read (1)
Start Condition
Repeated Start Condition
t _{Write (0)}
Continuation of protocol
G _{s Master-to-Slave}
Slave-to-Master
A ^t ₁
7
s _en ^{S Slave Address}
11
WA
8
1
Command Code A
I²C Write Protocol
8
Data Byte
1
1
A ^... P
am ^{nt 1}
7
co ^{S Slave Address}
11
RA
8
Data
1
8
A
Data
I²C Read Protocol
l ₇
a Slave Address
11
WA
8
Command Code
11
A Sr
7
Slave Address
11
RA
ic 8
1
Data
A
n _{I2C Read Protocol — Combined Format}
Tech ^{Figure 15. I2C Protocols}
1
1
A ^... P
8
1
1
Data
A ^... P
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r
r
www.taosinc.com
Copyright E 2011, TAOS Inc.
15