AS3668_07 Datasheet, PDF (25/59 Pages) ams AG – 4 Channel Breathlight Controller

AS3668
Data Sheet - Detailed Description
Figure 34. Reading n Bytes from AS3668
From Master to Slave
From Slave to Master Acknowledge
from AS3668 ⁰
S
Slave Address
R/W A
Autoincrement
Memory Word
Address
Acknowledge
from Master ⁰
First Data Byte
A
Stop reading
Not Acknowledge
from Master
1
n Bytes
Second Data Byte
/A P
1
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
AS3668 Registers
Autoincrement
to next address
8.6.3 I²C Device Address Selection
The AS3668 features two I²C slave addresses without having a dedicated address selection pin. The selection of the I²C address is done with
the interconnection of AS3668 to the bus lines shown in Figure 35 below. The serial interface logic inside AS3668 is able to distinguish between
a direct I2C connection to the master or a second option where data and clock line are crossed. Therefore it is only possible to address a
maximum of two AS3668 slaves on one I²C bus.
Figure 35. I²C Address Selection Application Diagram
DEVICE 1
DEVICE 2
The I²C addresses for the devices in the different connection modes can be found in Table 22.
Table 22. I²C Addresses for AS3668
DEVICE Number
7 bit I²C address
8 Bit read address
8 Bit write address
1(default)
0x42
0x85
0x84
2
0x43
0x87
0x86
8.7 Operating Modes
Due to the reason that AS3668 has no dedicated enable or power - on pin the device is basically controlled with the I²C signal lines SDA and
SCL. If the voltages on these pins are less than VPOR_PERI for > tPOR_DEB and GPIO/AUDIO_IN input is low, the AS3668 is in shut down
mode with a minimized current consumption of IVBAT = 1μA (typ.). All blocks inside AS3668 are basically switched off except the power up reset
circuit is always active.
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