STTS751 register summary

STTS751

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Doc ID 16483 Rev 5

4.1

STTS751 register formats and details

The STTS751 register set is comprised of the 16 addresses shown in Table 9. The

individual registers are accessed by transferring their addresses via the SMBus interface as

shown in Section 3.2, 3.3, and 3.4. In the case of the RECEIVE byte sequence

(Section 3.5) the address used is the address sent in the previous WRITE, READ or SEND

byte sequence.

An example read sequence of the Therm hysteresis register, address 21h, with its default

value, 0Ah, is shown below. The slave address used is 90h. The gray data is sent by the

STTS751 while the white data is sent by the host.

Note:

All eight bits are used to select the register.

4.2

Temperature register format

The temperature data is a 12-bit number and is stored in two's complement format spanning

the high byte and low byte registers as shown in Table 11.

The integer portion of the temperature is stored in the high byte, and the fractional portion in

the low byte. The lower four bits of the low byte will always read 0. At power-up, the

STTS751 defaults to 10-bit resolution. Thus, bits b5 and b4 of the lower byte will also read 0

until the device is configured to a higher resolution (via the Tres bits in the configuration

register).

Table 10.

Pointer register format

START

SLAVE

ADDRESS

WR ACK

REGISTER

ADDRESS

ACK START

SLAVE

ADDRESS

RD ACK

DATA

NACK STOP

1001_000

0

0010_0001

1001_000

1

0000_1010

Table 11.

Temperature register (two’s complement)

ADDR

(hex)

R/W

Register

b7

b6

b5

b4

b3

b2

b1

b0

Power-up

default

(hex)

00

R

Temperature - high byte

sign

64 °C

32 °C

16 °C

8 °C

4°C

2 °C

1 °C

00

02

R

Temperature - low byte

¼ °C

0

0

0

0

00