EMC2102 Datasheet, PDF (34/52 Pages) SMSC Corporation – RPM-Based Fan Controller with HW Thermal Shutdown

RPM-Based Fan Controller with HW Thermal Shutdown
Datasheet
6.3
Critical/Thermal Shutdown Temperature Register
Table 6.4 Critical/Thermal Shutdown Temperature Register
ADDRESS REGISTER
B7
B6
B5
B4
B3
04h
Critical/Therm Sign 64
32
16
8
al Shutdown
Temperature
B2 B1 B0
4
2
1
DEFAULT
7Fh
(+127°C)
6.4
The Critical/Thermal Shutdown Temperature Register is a read-only register that stores the Voltage
Programmable Threshold temperature used in the Thermal / Critical Shutdown circuitry. The contents
of the register reflect the calculated temperature based on the TRIP_SET voltage. This register is
updated at the end of every monitoring cycle based on the current value of TRIP_SET. The register
value reflects the exact threshold temperature.
The data format will match the selected format of the temperature data registers as shown in Table 6.3.
Configuration Register
Table 6.5 Configuration Register
ADDRESS REGISTER B7 B6 B5
B4
B3
B2
B1 B0 DEFAULT
20h
Configuration QUEUE[1:0] SYS3 SYS2 SYS1 FORMAT -
LOCK 80h
The Configuration Register controls the basic functionality of the EMC2102. The bits are described
below. The Configuration Register is software locked.
Bit 7-6 - QUEUE[1:0] - determines how many consecutive out-of-limit errors must occur on the
hardware selected and software enabled temperature channels before the SYS_SHDN# pin is
asserted (see Table 5.2). The queue applies to all enabled channels simultaneously and will trigger the
SYS_SHDN# pin if there are four consecutive measurements with any or all channels exceeding their
corresponding limits.
QUEUE1:0]
1
0
0
1
1
Table 6.6 Fault Queue
0
NUMBER OF FAULTS
0
1
1
2
0
4 (default)
1
8
Bit 5 - SYS3 - enables the high temperature limit for the External Diode 3 channel to trigger the Critical
/ Thermal Shutdown circuitry (see Section 5.7).
„ ‘0’ (default) - the External Diode 3 channel high limit will not be linked to the SYS_SHDN# pin. If
the temperature exceeds the limit, the ALERT# pin will be asserted normally.
Revision 1.95 (10-19-06)
34
DATASHEET
SMSC EMC2102