SE97TP datasheet(11/55 Pages) NXP

11 / 55 page

SE97_7

Product data sheet

Rev. 07 — 29 January 2010

11 of 55

NXP Semiconductors

SE97

DDR memory module temp sensor with integrated SPD, 3.3 V

– Competitor devices: Compares the Alarm Window with temperature register at any

time, so they get the EVENT output immediately when new Tth(crit) and EVENT

output are set at the same time.

– Work-around: Wait at least 125 ms before enabling EVENT output (EOCTL = 1).

Intel will change Nehalem BIOS so that Tth(crit) is set for more than 125 ms before

EVENT output is enabled and Event value is checked.

1. Set Tth(crit).

2. Doing something else (make sure that exceeds 125 ms).

3. Enable the EVENT output (EOCTL = 1).

4. Wait 20

μs.

5. Read Event value.

– SE97B will compare alarm window and temperature register immediately.

7.3.3 EVENT operation modes

7.3.3.1

Comparator mode

In comparator mode, the EVENT output behaves like a window-comparator output that

asserts when the temperature is outside the window (e.g., above the value programmed in

the Upper Boundary Alarm Trip register or below the value programmed in the Lower

Boundary Alarm Trip register or above the Critical Alarm Trip resister if Tth(crit) only is

selected). Reads/writes on the registers do not affect the EVENT output in comparator

mode. The EVENT signal remains asserted until the temperature goes inside the alarm

window or the window thresholds are reprogrammed so that the current temperature is

within the alarm window.

The comparator mode is useful for thermostat-type applications, such as turning on a

cooling fan or triggering a system shutdown when the temperature exceeds a safe

operating range.

7.3.3.2

Interrupt mode

In interrupt mode, EVENT asserts whenever the temperature crosses an alarm window

threshold. After such an event occurs, writing a 1 to the Clear EVENT bit (CEVNT) in the

configuration register de-asserts the EVENT output until the next trigger condition occurs.

In interrupt mode, EVENT asserts when the temperature crosses the alarm upper

boundary. If the EVENT output is cleared and the temperature continues to increase until

it crosses the critical temperature threshold, EVENT asserts again. Because the

temperature is greater than the critical temperature threshold, a Clear EVENT command

does not clear the EVENT output. Once the temperature drops below the critical

temperature, EVENT de-asserts immediately.

• Advisory note:

– NXP device: If the EVENT output is not cleared before the temperature goes

above the critical temperature threshold EVENT de-asserts immediately when

temperature drops below the critical temperature.

– Competitor devices: If the EVENT output is not cleared before or when the

temperature is in the critical temperature threshold, EVENT will remain asserted

after the temperature drops below the critical temperature until a Clear EVENT

command.

SE97TP Datasheet(PDF) 11 Page - NXP Semiconductors

SE97TP Datasheet(HTML) 11 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 54 55

Datasheet Download

Link URL