Datasheet

LM87
www.ti.com SNAS034J –APRIL 2000–REVISED MARCH 2013
Configuration Register 1—Address 40h
Power on default – <7:0> = 00001000 binary
Bit Name Read/Write Description
0 Start Read/Write A one enables startup of monitoring operations, a zero puts the part in standby mode.
Note: The outputs of Interrupt pins will not be cleared if the user writes a zero to this location after
an interrupt has occurred, unlike the “INT_Clear” bit.
At start up, limit checking functions and scanning begin. Note, all limits should be set in the Value
RAM before setting this bit HIGH.
1 INT# Enable Read/Write A one enables the INT# Interrupt output.
2 THERM# Enable Read/Write A one enables the THERM# Interrupt output.
3 INT#_Clear Read/Write A one disables the INT# output without affecting the contents of Interrupt Status Registers. The
device will stop monitoring. It will resume upon clearing of this bit.
4 RESET# Read/Write A one outputs a 20 ms minimum active low reset signal at RESET#. This bit is cleared once the
pulse has gone inactive.
5 Reserved Read/Write
6 THERM#_Clear Read/Write A one disables the THERM# output without affecting the contents of Interrupt Status Registers.
7 INITIALIZATION Read/Write A one restores power on default values to the Configuration Register, Interrupt Status Registers,
Interrupt Mask Registers, CI Clear Register, VID/Fan Divisor Register, VID4, Temperature
Configuration Register, and the Extended Mode Registers. This bit clears itself since the power on
default is zero.
Interrupt Status Register 1—Address 41h
Power on default – <7:0> = 0000 0000 binary
Bit Name Read/Write Description
0 +2.5Vin Read Only A one indicates a High or Low limit has been exceeded.
1 Vccp1 Read Only A one indicates a High or Low limit has been exceeded.
2 Vcc Read Only A one indicates a High or Low limit has been exceeded.
3 +5Vin Read Only A one indicates a High or Low limit has been exceeded.
4 Int. Temp. Read Only A one indicates a High or Low limit has been exceeded.
5 Ext. Temp. Read Only A one indicates a High or Low limit has been exceeded.
6 FAN1/AIN1 Read Only A one indicates the fan count limit has been exceeded or an AIN1 High or Low limit has been
exceeded.
7 FAN2/AIN2 Read Only A one indicates the fan count limit has been exceeded or an AIN2 High or Low limit has been
exceeded.
Interrupt Status Register 2—Address 42h
Power on default – <7:0> = 0000 0000 binary
Bit Name Read/Write Description
0 +12Vin Read Only A one indicates a High or Low limit has been exceeded.
1 Vccp2 Read Only A one indicates a High or Low limit has been exceeded.
2 Reserved Read Only
3 Reserved Read Only
4 CI Read Only A one indicates the CI (Chassis Intrusion) input has gone high.
5 THERM# Read Only A one indicates the THERM# input has been pulled low by external circuitry.
6 D1 Fault Read Only A one indicates the D1 inputs are shorted to Vcc or open circuit.
7 D2 Fault Read Only A one indicates the D2 inputs are shorted to Vcc or open circuit.
Copyright © 2000–2013, Texas Instruments Incorporated Submit Documentation Feedback 31
Product Folder Links: LM87