se97b NXP Semiconductors, se97b Datasheet - Page 28

• Manufacturer Part Number: se97b
• Description: Ddr Memory Module Temp Sensor With Integrated Spd
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SE97B_1
Product data sheet
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).
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:
Table 15
negative temperature for two scenarios of status bits: status bits = 000b and
status bits = 111b.
Table 15.
Temperature
+125 °C
+25 °C
+1 °C
+0.25 °C
+0.125 °C
0 °C
−0.125 °C
−0.25 °C
−1 °C
−20 °C
−25 °C
−55 °C
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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.
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).
lists the examples of the content of the temperature data register for positive and
Degree Celsius and Temperature Data register
Content of Temperature Data register
Status bits = 000b
Binary
000 0 01111101 000 0
000 0 00011001 000 0
000 0 00000001 000 0
000 0 00000000 010 0
000 0 00000000 001 0
000 0 00000000 000 0
000 1 11111111 111 0
000 1 11111111 110 0
000 1 11111111 000 0
000 1 11110100 000 0
000 1 11100111 000 0
000 1 11001001 000 0
Rev. 01 — 27 January 2010
DDR memory module temp sensor with integrated SPD
Hex
07D0h
0190h
0010h
0004h
0002h
0000h
1FFEh
1FFCh
1FF0h
1F40h
1E70h
1C90h
Status bits = 111b
Binary
111 0 01111101 000 0
111 0 00011001 000 0
111 0 00000001 000 0
111 0 00000000 010 0
111 0 00000000 001 0
111 0 00000000 000 0
111 1 11111111 111 0
111 1 11111111 110 0
111 1 11111111 000 0
111 1 11110100 000 0
111 1 11100111 000 0
111 1 11001001 000 0
© NXP B.V. 2010. All rights reserved.
SE97B
Hex
E7D0h
E190h
E010h
E004h
E002h
E000h
FFFEh
FFFCh
FFF0h
FF40h
FE70h
FC90h
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