Analog Devices dBCool ADT7473 Manual page 25

THERM
TIMER LIMIT
(REGISTER 0x7A)
Configuring the THERM Pin as Bidirectional
In addition to monitoring THERM as an input, the ADT7473
can optionally drive THERM low as an output. When
PROCHOT is bidirectional, THERM can be used to throttle th
processor by asserting PROCHOT . The user can preprogram
system-critical thermal limits. If the temperature exceeds a
thermal limit by 0.25°C, THERM asserts low. If the tempera
is still above the thermal limit on the next monitoring cycle,
THERM stays low. THERM remains asserted low until the
temperature is equal to or below the thermal limit. Beca
temperature for that channel is measured only once for every
monitoring cycle after THERM asserts, it is guaranteed to
remain low for at least one monitoring cycle.
The THERM pin can be configured to assert low, if the
Remote 1, local, or Remote 2 THERM temperature limits are
exceeded by 0.25°C. The THERM temperature limit registers
are at Register 0x6A, Register 0x6B, and Register 0x6C,
respectively. Setting Bit 5, Bit 6, and Bit 7 of Configuration
Register 5 (0x7C) makes THERM bidirectional for the
Remote 1, local, and Remote 2 temperature channels,
respectively. Figure 31 shows how the THERM pin asserts low
as an output in the event of a critical over temperature.
2.914s
1.457s
728.32ms
364.16ms
182.08ms
91.04ms
45.52ms
22.76ms
2 6
0 1 3 4 5 7
CO
Figure 30. Functional Block Diag
use the
7 6 5 4 3 2 1 0
MPARATOR
F4P BIT (BIT 5)
IN
OUT
INTERRUPT STATUS
REGISTER 2
LATCH
RESET
CLEAR ED
1 = MASK
ON RE AD
F4P BIT (BIT 5)
INTERRUPT MASK REGISTER 2
(REGISTER 0x75)
ram of the AD T7473 THERM Monitoring Circuitry
THERM LIMIT
0.25°C
THERM LIMIT
e
THERM
ture
An alternative method of disabling THERM is to progr
temperatu
THERM
or −128°C or less in twos complem
THERM temperature limit values less than –63°C or –128°C,
respectively, THERM is disabled. THERM can also be disabled
by setting Bit 1 of Configuration Register 3 (0x78) to 0.
Rev. A | Page 25 of 76
2.914s
1.457s
728.32ms
364.16ms THERM TIMER
(REGISTER 0x79)
182.08ms
91.04ms
45.52ms
22.76ms
THERM
THERM TIMER CLEARED ON READ
SMBALERT
TEMP
MONITORING
CYCLE
Figure 31. Asserting THERM as an Output,
Based on Tripping THERM Limits
re limit to –64°C or less in
ent mode; that is, for
ADT7473
am the
Offset 64 mode,