SE98A Datasheet, PDF (18/43 Pages) NXP Semiconductors – DDR memory module temp sensor, 1.7 V to 3.6 V

NXP Semiconductors
SE98A
DDR memory module temp sensor, 1.7 V to 3.6 V
8.3 Configuration register (01h, 16-bit read/write)
Table 8.
Bit
Symbol
Default
Access
Bit
Symbol
Default
Access
Configuration register (address 01h) bit allocation
15
14
13
12
RFU
0
0
0
0
R
R
R
R
7
6
5
4
CTLB
AWLB
CEVNT
ESTAT
0
0
0
0
R/W
R/W
R/W
R/W
11
0
R
3
EOCTL
0
R/W
10
9
HEN[1:0]
0
0
R/W
R/W
2
1
CVO
EP
0
0
R/W
R/W
8
SHMD
0
R/W
0
EMD
0
R/W
Table 9. Configuration register (address 01h) bit description
Bit Symbol Description
15:11 RFU
reserved for future use; must be ‘0’.
10:9 HEN
Hysteresis Enable
00 — Disable hysteresis (default)
01 — Enable hysteresis at 1.5 °C
10 — Enable hysteresis at 3 °C
11 — Enable hysteresis at 6 °C
When enabled, hysteresis is applied to temperature movement around trigger
points. For example, consider the behavior of the ‘Above Alarm Window’ bit
(bit 14 of the Temperature register) when the hysteresis is set to 3 °C. As the
temperature rises, bit 14 will be set to 1 (temperature is above the alarm
window) when the Temperature register contains a value that is greater than
the value in the Alarm Temperature Upper Boundary register. If the
temperature decreases, bit 14 will remain set until the measured temperature
is less than or equal to the value in the Alarm Temperature Upper Boundary
register minus 3 °C. (Refer to Figure 6 and Table 10).
Similarly, the ‘Below Alarm Window’ bit (bit 13 of the Temperature register) will
be set to 0 (temperature is equal to or above the Alarm Window Lower
Boundary Trip register) when the value in the Temperature register is equal to
or greater than the value in the Alarm Temperature Lower Boundary register.
As the temperature decreases, bit 13 will be set to 1 when the value in the
Temperature register is equal to or less than the value in the Alarm
Temperature Lower Boundary register minus 3 °C. Note that hysteresis is also
applied to EVENT pin functionality.
When either of the Critical Trip or Alarm Window lock bits is set, these bits
cannot be altered until unlocked.
8
SHMD Shutdown Mode.
0 — Enabled Temperature Sensor (default)
1 — Disabled Temperature Sensor
When shut down, the thermal sensor diode and Analog-to-Digital Converter
(ADC) are disabled to save power, no events will be generated. When either of
the Critical Trip or Alarm Window lock bits is set, this bit cannot be set until
unlocked. However, it can be cleared at any time.
SE98A_2
Product data sheet
Rev. 02 — 6 August 2009
© NXP B.V. 2009. All rights reserved.
18 of 43