Address A6–A0

Description

2Ah

Reserved

2Bh

+2.5V High Limit/External Temperature 2 High Limit

2Ch

+2.5V Low Limit/External Temperature 2 Low Limit

2Dh

Vccp1 High Limit

2Eh

Vccp1 Low Limit

2Fh

+3.3V High Limit

30h

+3.3V Low Limit

31h

+5V High Limit

32h

+5V Low Limit

33h

+12V High Limit

34h

+12V Low Limit

35h

Vccp2 High Limit

36h

Vccp2 Low Limit

37h

External Temperature 1 High Limit

38h

External Temperature 1 Low Limit

39h

Internal Temperature High Limit

3Ah

Internal Temperature Low Limit

3Bh

FAN1Count Limit/AIN1 High Limit

Note: It is the number of counts of the internal clock for the Low Limit of the fan speed.

3Ch

FAN2 Fan Count Limit/AIN2 High Limit

Note: It is the number of counts of the internal clock for the Low Limit of the fan speed.

3Dh

Reserved

3Eh

Company Identification. The number in this register identifies National Semiconductor LM87 (0000

0010)

3Fh

Stepping Register LM87 revision number 06h(0000 0110)

Note: Setting all ones to the high limits for voltages and fans (0111 1111

binary for temperature) means interrupts will never be generated

except the case when voltages go below the low limits.

For voltage input high limits, the device is doing a greater than com-

parison. For low limits, however, it is doing a less than or equal to

comparison.

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