se98a NXP Semiconductors, se98a Datasheet - Page 9

• Manufacturer Part Number: se98a
• Description: Ddr Memory Module Temp Sensor, 1.7 V To 3.6 V
• Manufacturer: NXP Semiconductors

NXP Semiconductors
SE98A_1
Product data sheet
7.3.3.1 Comparator mode
7.3.3.2 Interrupt mode
7.3.3 Event operation modes
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 T
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.
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 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.
•
– Competitor devices: Compares the alarm limit with temperature register at any
– Work-around: Wait at least 125 ms before enabling EVENT output. Intel will
– SE98B will compare alarm window and temperature register immediately after
Advisory notification:
– NXP device: If the EVENT output is not cleared before the temperature goes above
time, so they get the EVENT output immediately when new T
EVENT bit 3 (EOCTL) are set at the same time.
change Nehalem BIOS so that T
EVENT bit 3 (EOCTL) is enabled and Event value is checked.
1. Set T
2. Doing something else (make sure that exceeds 125 ms).
3. Enable the EVENT output bit 3 (EOCTL = 1).
4. Wait 20 s.
5. Read Event value.
setting.
the critical temperature threshold EVENT de-asserts immediately when
temperature drops below the critical temperature.
th(crit)
.
Rev. 01 — 5 March 2009
DDR memory module temp sensor, 1.7 V to 3.6 V
th(crit)
is set for more than 125 ms before
th(crit)
© NXP B.V. 2009. All rights reserved.
th(crit)
and
SE98A
only is
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