THS7347

SLOS531B

– MAY 2007 – REVISED OCTOBER 2011

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WRITE AND READ EXAMPLES

These examples illustrate the proper way to write to and read from the THS7347.

WRITING TO THE THS7347

An I2C master initiates a write operation to the THS7347 by generating a start condition (S) followed by the

THS7347 I2C address, in MSB-first order, followed by a '0' to indicate a write cycle. After receiving an

acknowledge from the THS7347, the master presents the subaddress (channel) it wants to write, consisting of

one byte of data, MSB first. The THS7347 acknowledges the byte after completion of the transfer. Finally, the

master presents the data it wants to write to the register (channel) and the THS7347 acknowledges the byte. The

I2C master then terminates the write operation by generating a stop condition (P). Note that the THS7347 does

not support multi-byte transfers. To write to all three channels (or registers), this procedure must be repeated for

each register, one series at a time (that is, repeat steps 1 through 8 for each channel).

Step 1

0

I2C Start (Master)

S

Step 2

7

6

5

4

3

2

1

0

I2C General Address (Master)

0

1

0

1

1

X

X

0

Where each X logic state is defined by I2C-A1 and I2C-A0 pins being tied to either VDD or GND.

Step 3

9

I2C Acknowledge (Slave)

A

Step 4

7

6

5

4

3

2

1

0

I2C Write Channel Address (Master)

0

0

0

0

0

Addr

Addr

Addr

Where Addr is determined by the values shown in Table 2.

Step 5

9

I2C Acknowledge (Slave)

A

Step 6

7

6

5

4

3

2

1

0

I2C Write Data (Master)

Data

Data

Data

Data

Data

Data

Data

Data

Where Data is determined by the values shown in Table 3.

Step 7

9

I2C Acknowledge (Slave)

A

Step 8

0

I2C Stop (Master)

P

22

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