LM78 National Semiconductor, LM78 Datasheet - Page 29

• Manufacturer Part Number: LM78
• Description: Microprocessor System Hardware Monitor
• Manufacturer: National Semiconductor

Functional Description
Address A6–A0
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
3E–3Fh
voltages go below the low limits.
For voltage input high limits, the device is doing
2Ch
2Dh
3Ch
3Dh
29h
2Ah
2Bh
2Eh
2Fh
30h
31h
32h
33h
34h
35h
36h
37h
38h
39h
3Ah
3Bh
Address A6–A0 with
Auto-Increment
7E–7Fh
6Ch
6Dh
7Ch
7Dh
69h
6Ah
6Bh
6Eh
6Fh
70h
71h
72h
73h
74h
75h
76h
77h
78h
79h
7Ah
7Bh
(Continued)
>
comparison. For low limits, however, it is doing
Note: This location stores the number of counts of the internal clock per
revolution.
FAN2 reading
Note: This location stores the number of counts of the internal clock per
revolution.
FAN3 reading
Note: This location stores the number of counts of the internal clock per
revolution.
IN0 High Limit
IN0 Low Limit
IN1 High Limit
IN1 Low Limit
IN2 High Limit
IN2 Low Limit
IN3 High Limit
IN3 Low Limit
IN4 High Limit
IN4 Low Limit
-IN5 High Limit
-IN5 Low Limit
-IN6 High Limit
-IN6 Low Limit
Over Temperature Limit (High)
Temperature Hysteresis Limit (Low)
FAN1 Fan Count Limit
Note: It is the number of counts of the internal clock for the Low Limit of
the fan speed.
FAN2 Fan Count Limit
Note: It is the number of counts of the internal clock for the Low Limit of
the fan speed.
FAN3 Fan Count Limit
Note: It is the number of counts of the internal clock for the Low Limit of
the fan speed.
Reserved
29
Description
comparison.
www.national.com