Analog Devices ADT7473 Manual page 62

ADT7473
Table 24. Register 0x40—Configuration Register 1 (Power-On Default = 0x01)
Bit Name R/W
1
<0> STRT Read/write
<1> LOCK Write once
<2> RDY Read-only
<3> FSPD Read/write
<4> VxI Read/write
<5> FSPDIS Read/write
<6> TODIS Read/write
<7> RES
1 Bit 0 (STRT) of 0x40, Configuration Register 1 remains writable after lock bit is set.
Table 25. Register 0x41—Interrupt Status Register 1 (Power-On Default = 0x00)
Bit Name R/W
<1> V Read-only
CCP
<2> V Read-only
CC
<4> RIT Read-only
<5> LT Read-only
<6> R2T Read-only
<7> OOL Read-only
Table 26. Register 0x42—Interrupt Status Register 2 (Power-On Default = 0x00)
Bit Name R/W
<1> OVT Read-only
<2> FAN1 Read-only
<3> FAN2 Read-only
<4> FAN3 Read-only
<5> F4P Read-only
Read/write
Read-only
<6> D1 Read-only
<7> D2 Read-only
Description
Logic 1 enables monitoring and PWM control outputs based on the limit settings programmed.
Logic 0 disables monitoring and PWM control based on the default power-up limit settings.
This bit will not be locked when Bit 1 (LOCK bit) has been written.
Logic 1 locks all limit values to their current settings. Once this bit is set, all lockable registers become read-
only and cannot be modified until the ADT7473 is powered down and powered up again. This prevents
rogue programs, such as viruses, from modifying critical system limit settings. (Lockable.)
This bit is set to 1 by the ADT7473 to indicate only that the device is fully powered up and ready to begin
system monitoring.
When set to 1, this bit runs all fans at full speed. Power-on default = 0. This bit is not locked at any time.
BIOS should set this bit to a 1 when the ADT7473 is configured to measure current from an ADI ADOPT
controller and to measure the CPU's core voltage. This bit allows monitoring software to display CPU watts
usage. (Lockable.)
Logic 1 disables fan spin-up for two TACH pulses. Instead, the PWM outputs go high for the entire fan spin-
up timeout selected.
When this bit is set to 1, the SMBus timeout feature is enabled. This allows the ADT7473 to be used with
SMBus controllers that cannot handle SMBus timeouts. (Lockable.)
Reserved.
Description
V = 1 indicates the V high or low limit has been exceeded. This bit is cleared on a read of the status
CCP CCP
register only if the error condition has subsided.
V = 1 indicates the V high or low limit has been exceeded. This bit is cleared on a read of the status
CC CC
register only if the error condition has subsided.
RIT = 1 indicates the Remote 1 low or high temperature has been exceeded. This bit is cleared on a read of
the status register only if the error condition has subsided.
LT = 1 indicates the local low or high temperature has been exceeded. This bit is cleared on a read of the
status register only if the error condition has subsided.
R2T = 1 indicates the Remote 2 low or high temperature has been exceeded. This bit is cleared on a read of
the status register only if the error condition has subsided.
OOL = 1 indicates an out-of-limit event has been latched in Status Register 2. This bit is a logical OR of all
status bits in Status Register 2. Software can test this bit in isolation to determine whether any of the voltage,
temperature, or fan speed readings represented by Status Register 2 are out-of-limit, which saves the need to
read Status Register 2 every interrupt or polling cycle.
Description
OVT = 1 indicates one of the THERM overtemperature limits is exceeded. This bit is cleared on a read of the
status register when the temperature drops below THERM –T
FAN1 = 1 indicates Fan 1 has dropped below minimum speed or has stalled. This bit is not set when the
PWM1 output is off.
FAN2 = 1 indicates Fan 2 has dropped below minimum speed or has stalled. This bit is not set when the
PWM2 output is off.
FAN3 = 1 indicates Fan 3 has dropped below minimum speed or has stalled. This bit is not set when the
PWM3 output is off.
F4P = 1 indicates Fan 4 has dropped below minimum speed or has stalled. This bit is not set when the PWM3
output is off.
When Pin 9 is programmed as a GPIO output, writing to this bit determines the logic output of the GPIO.
If Pin 9 is configured as the THERM timer input for THERM monitoring, then this bit is set when the THERM
assertion time exceeds the limit programmed in the THERM limit register (Reg. 0x7A).
D1 = 1 indicates either an open or short circuit on the Thermal Diode 1 inputs.
D2 = 1 indicates either an open or short circuit on the Thermal Diode 2 inputs.
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