ADT7476
Rev. B | Page 59 of 72
Table 28. Register 0x42—Interrupt Status Register 2 (Power-On Default = 0x00)
Bit Name
R/W
Description
[0] 12
V/VC
Read-only A 1 indicates that the 12 V high or low limit has been exceeded. This bit is cleared on a read of the status
register only if the error condition has subsided. If Pin 21 is configured as VID5, this bit is the VID change
bit. This bit is set when the levels on VID0 to VID5 are different than they were 11 μs previously. This pin
can be used to generate an SMBALERT whenever the VID code changes.
[1]
OVT
Read-only
OVT = 1 indicates that one of the THERM overtemperature limits has been exceeded. This bit is cleared on
a read of the status register when the temperature drops below THERM − T
HYST
.
[2] FAN1
Read-only
FAN1 = 1 indicates that Fan 1 has dropped below minimum speed or has stalled. This bit is not set when
the PWM 1 output is off.
[3]
FAN2
Read-only
FAN2 = 1 indicates that Fan 2 has dropped below minimum speed or has stalled. This bit is not set when
the PWM 2 output is off.
[4]
FAN3
Read-only
FAN3 = 1 indicates that Fan 3 has dropped below minimum speed or has stalled. This bit is not set when
the PWM 3 output is off.
[5] F4P
Read-only When Pin 14 is programmed as a TACH4 input, F4P = 1 indicates that Fan 4 has dropped below minimum
speed or has stalled. This bit is not set when the PWM3 output is off.
THERM
Read-only
If Pin 14 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 (0x7A).
GPIO6 R/W
When Pin 14 is programmed as the GPIO6 output, writing to this bit determines the logic output of GPIO6.
When GPIO6 is programmed as an input, this bit reflects the value read by GPIO6.
[6]
D1
Read-only
D1 = 1 indicates either an open or short circuit on the Thermal Diode 1 inputs.
[7]
D2
Read-only
D2 = 1 indicates either an open or short circuit on the Thermal Diode 2 inputs.
Table 29. Register 0x43—VID Code Register (Power-On Default = 0x1F )
Bit
Name
R/W
Description
[4:0]
VID[4:0]/
GPIO
Read-only
The VID inputs from the CPU indicate the expected processor core voltage. On power-up, these bits
reflect the state of the VID pins, even if monitoring is not enabled.
When enabled as a GPIO, these bits are writable.
[5]
VID5
Read-only
Reads VID5 from the CPU when Bit 7 = 1. If Bit 7 = 0, the VID5 bit always reads back 0 (power-on default).
[6]
THLD
R/W
Selects the input switching threshold for the VID inputs.
THLD = 0 selects a threshold of 1 V (V
OL
< 0.8 V, V
IH
> 1.7 V).
THLD = 1 lowers the switching threshold to 0.6 V (V
OL
< 0.4 V, V
IH
> 0.8 V).
[7]
VIDSEL
R/W
VIDSEL = 0 configures Pin 21 as the 12 V measurement input (default).
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