SX8724C Datasheet, PDF (39/67 Pages) Semtech Corporation – ZoomingADC for sensing data acquisition

ADVANCED COMMUNICATIONS & SENSING
9.2.1 Address Set Externally
SX8724C
ZoomingADC for sensing data acquisition
DATASHEET
Bit:
Slave address:
65 4 3 2 1 0
100 XX 01
Address bit[0] set to 1
Address bit[1] set to 0
D0
D1
GPIO
Figure 20. Example of I2C address set by external resistors
The GPIO are set as ouput low at startup, so a resistor should be connected to the pad to avoid shortcut at startup.
After startup, the master I2C can send a command (0x96 in RegExtAdd[0x43]) at the default I2C address to change I2C
mode and set D0 and D1 as input address bits.
If several SX87xx devices are connected on the same bus, the master MCU must send the command to each device
simultaneousely using the default address. All SX87xx devices will receive the command at the same time. The master
MCU must ensure that the command has been received by asking each slave device at their new address.
9.3 I2C General Call Reset
The device respond to the I2C general call address (0000000) if the eighth bit is '0'. The devices acknowledge the
general call address and respond to commands in the second byte. If the second byte is 00000110 (06h), the device
reset the internal registers and enter power-down mode.
S
W
T
R
A
I
R DEVICE T
T ADDRESS E
REGISTER
ADDRESS
S
T
O
P
SDA
M
LA
A
S
SC
C
B
BK
K
0x00
0x06
Figure 21. I2C General Call reset frame
Revision 1.01
© Semtech
January 2011
Page 39
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