Rev. 1.20

13

June 17, 2016

HT7M2126/27/36/56/76

SCL

SDA

SCL

SDA

1

2

3

4

56

7

8

1

2

34

5

6

78

0

01

1

00

W

A

C

K

00

00

0

00

1

1

S

A

C

K

Address Byte

HT7M21xx

Configuration Pointer

HT7M21xx

1

2

3

4

56

7

8

1

2

34

5

6

78

1

1

1

1

100

A

C

K

0

0

01

0

00

P

0

A

C

K

MSB Data

HT7M21xx

LSB Data

HT7M21xx

0

Note:Thisisanexampleroutine:(SeeAppendixB:“SourceCode”)

i2c_start();

// send START command

i2c_write(AddressByte & 0xFE); // WRITE Command

// also, make sure bit 0 is cleared ‘0’

i2c_write(0x01);

// Write CONFIG Register

i2c_write(0x7c); //Writeconfigdata

i2c_write(0x10); //Writeconfigdata

i2c_stop();

// send STOP command

• Reading the CONFIG Register

SCL

SDA

SCL

SDA

12 3 4 5 67 8

1 2 3 45

6 7 8

0 0 1 1 0 0W

A

C

K

00 00 0 00 1

1

S

A

C

K

Address Byte

HT7M21xx

Configuration Pointer HT7M21xx

12 3 4 5 67 8

1 2 3 45

6 7 8

0 0 1 1 0 0R

A

C

K

01 11 1 10 0

1

S

A

C

K

Address Byte

HT7M21xx

MSB Data

HT7M21xx

1 2 34 5

6 78

0 0 0 10 00 0

N

A

K

P

LSB Data

HT7M21xx

Note: 1. It is not necessary to select the register pointer if it was set from the previous read/write.

2.Thisisanexampleroutine:(SeeAppendixB:“SourceCode”)

i2c_start();

// send START command

i2c_write(AddressByte & 0xFE);

// WRITE Command

// also, make sure bit 0 is cleared ‘0’

i2c_write(0x01);

// Write CONFIG Register

i2c_start();

// send Repeat START command

i2c_write(AddressByte | 0x01);

// READ Command