Datasheet

LM87

SNAS034J –APRIL 2000–REVISED MARCH 2013

www.ti.com

Internal Registers of the LM87

Table 1. The internal registers and their corresponding internal LM87 addresses are as follows:

Address Value

Internal Temp. Hardware High 13h 0100 0110 70 °C Default - User adjustable. Lockable by setting bit 1

Limit of register 4Ah.

External Temp. Hardware High 14h 0101 0101 85 °C Default - User adjustable. Lockable by setting bit 2

Limit of register 4Ah.

Test Register 15h 0000 0000

Channel Mode Register 16h 0000 0000

Internal Temp. Hardware High 17h 0100 0110 70 °C Default - User adjustable.

Limit

External Temp. Hardware High 18h 0101 0101 85 °C Default - User adjustable.

Limit

Value RAM DAC Data Register 19h 1111 1111 Defaults to full scale DAC setting.

Value RAM 1Ah-3Fh (See Value RAM—Address 19h–3Fh) Contains: monitoring

results (temperature, voltages, fan counts), WATCHDOG

limits, and Company/Stepping IDs

Company ID 3Eh 0000 0010 This designates the Texas Instruments LM87.

Revision 3Fh 0000 0110 Revisions of this device will start with 1 and increment by

one.

Configuration Register 1 40h 0000 1000

Interrupt Status Register 1 41h 0000 0000

Interrupt Status Register 2 42h 0000 0000

Interrupt Mask Register 1 43h 0000 0000

Interrupt Mask Register 2 44h 0000 0000

CI Clear Register 46h 0000 0000

VID0-3/Fan Divisor Register 47h 0101 XXXX The upper four bits set the divisor for Fan Counters 1 and

2. The lower four bits reflect the state of the VID0-VID3

inputs.

VID4 Register 49h 1000 000X The lower bit reflects the state of VID4 input.

Configuration Register 2 4Ah 0000 0000

Interrupt Status Register 1 4Ch 0000 0000

Mirror

Interrupt Status Register 2 4Dh 0000 0000

Mirror

SMBALERT# Enable 80h 0010 0000

Product Folder Links: LM87