LM3556_15 Datasheet, PDF (18/39 Pages) Texas Instruments – Synchronous Boost LED Flash Driver With High-Side Current Source

LM3556
SNVS796D – AUGUST 2011 – REVISED OCTOBER 2015
Programming (continued)
ack from slave
ack from slave
ack from slave
start msb Chip Address lsb w ack msb Register Add lsb ack msb DATA lsb
ack stop
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SCL
SDA
start
Id = 63h
w ack
addr = 0Ah
ack
W = Write (SDA = '0')
R = Read (SDA = '1')
Ack = Acknowledge (SDA Pulled Down By Either Master Or Slave)
ID= Chip Address, 63h For LM3556
Figure 31. Write Cycle
Data = 03h
ack stop
7.5.1.4 I²C-Compatible Chip Address
The device address for the LM3556 is 1100011 (63). After the START condition, the I²C-compatible master
sends the 7-bit address followed by an eighth read or write bit (R/W). R/W = 0 indicates a WRITE and R/W = 1
indicates a READ. The second byte following the device address selects the register address to which the data
will be written. The third byte contains the data for the selected register.
MSB
LSB
1
Bit 7
1
Bit 6
0
Bit 5
0
Bit 4
0
Bit 3
1
Bit 2
1
Bit 1
R/W
Bit 0
I²C Slave Address (chip address)
Figure 32. I²C-Compatible Device Address
7.5.1.5 Transferring Data
Every byte on the SDA line must be eight bits long, with the most significant bit (MSB) transferred first. Each byte
of data must be followed by an acknowledge bit (ACK). The acknowledge related clock pulse (9th clock pulse) is
generated by the master. The master releases SDA (HIGH) during the 9th clock pulse. The LM3556 pulls down
SDA during the 9th clock pulse, signifying an acknowledge. An acknowledge is generated after each byte has
been received.
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