SE97BTP datasheet(28/53 Pages) NXP

28 / 53 page

SE97B_1

Product data sheet

Rev. 01 — 27 January 2010

28 of 53

NXP Semiconductors

SE97B

DDR memory module temp sensor with integrated SPD

8.4 Temperature format

The temperature data from the temperature read back register is an 11-bit 2’s complement

word with the least significant bit (LSB) equal to 0.125

°C (resolution).

• A value of 019Ch will represent 25.75 °C

• A value of 07C0h will represent 124 °C

• A value of 1E64h will represent −25.75 °C.

The unused LSB (bit 0) is set to ‘0’. Bit 11 will have a resolution of 128

°C.

The upper 3 bits of the temperature register indicate Trip Status based on the current

temperature, and are not affected by the status of the EVENT output.

One of the ways to calculate the Temperature, Upper Boundary, Lower Boundary, and

Critical Alarm Trip values in

°C from the 12-bit Temp data is:

• If the SIGN bit = 0, then the temperature is positive,

(

°C) = +(Temp data) × 0.125 °C (0.250 °C for alarm registers).

• If the SIGN bit = 1, then the temperature is negative,

(

°C) = −(2’s complement of Temp data) × 0.125 °C (0.250 °C for alarm registers).

Table 15 lists the examples of the content of the temperature data register for positive and

negative temperature for two scenarios of status bits: status bits = 000b and

status bits = 111b.

Table 15.

Degree Celsius and Temperature Data register

Temperature

Content of Temperature Data register

Status bits = 000b

Status bits = 111b

Binary

Hex

Binary

Hex

+125

°C

000 0 01111101 000 0

07D0h

111 0 01111101 000 0

E7D0h

+25

°C

000 0 00011001 000 0

0190h

111 0 00011001 000 0

E190h

°C

000 0 00000001 000 0

0010h

111 0 00000001 000 0

E010h

+0.25

°C

000 0 00000000 010 0

0004h

111 0 00000000 010 0

E004h

+0.125

°C

000 0 00000000 001 0

0002h

111 0 00000000 001 0

E002h

°C

000 0 00000000 000 0

0000h

111 0 00000000 000 0

E000h

−0.125 °C

000 1 11111111 111 0

1FFEh

111 1 11111111 111 0

FFFEh

−0.25 °C

000 1 11111111 110 0

1FFCh

111 1 11111111 110 0

FFFCh

−1 °C

000 1 11111111 000 0

1FF0h

111 1 11111111 000 0

FFF0h

−20 °C

000 1 11110100 000 0

1F40h

111 1 11110100 000 0

FF40h

−25 °C

000 1 11100111 000 0

1E70h

111 1 11100111 000 0

FE70h

−55 °C

000 1 11001001 000 0

1C90h

111 1 11001001 000 0

FC90h

SE97BTP Datasheet(PDF) 28 Page - NXP Semiconductors

SE97BTP Datasheet(HTML) 28 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

Datasheet Download

Link URL