Rainbow Electronics LM81 - Manual (Page 31)

Functional Description
(Continued)
13.16 Value RAM — Address 15h–3Fh
Address A6–A0 Description
15h Manufacturers Test Register
19h DAC data register; power on default < 7:0 > =1111 1111 binary
20h +2.5Vin reading
21h Vccp1 reading
22h +3.3Vin reading
23h +5Vin reading
24h +12Vin reading
25h Vccp2 reading
26h Reserved reading
27h Temperature reading (8 MSBs)
28h FAN1 reading
Note: This location stores the number of counts of the internal clock per revolution.
29h FAN2 reading
Note: This location stores the number of counts of the internal clock per revolution.
2Ah Reserved
2Bh +2.5Vin High Limit
2Ch +2.5Vin Low Limit
2Dh Vccp1 High Limit
2Eh Vccp1 Low Limit
2Fh +3.3Vin High Limit
30h +3.3Vin Low Limit
31h +5Vin High Limit
32h +5Vin Low Limit
33h +12Vin High Limit
34h +12Vin Low Limit
35h Vccp2 High Limit
36h Vccp2 Low Limit
37h T_CRIT Limit (Extended Mode)
38h LOW Limit (Extended Mode)
39h HIGH Temperature Limit
3Ah HIHYST Temperature Limit
3Bh FAN1 Fan Count 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
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 (0000 0001)
3Fh Stepping Register LM81 revision number (0000 0011)
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 comparison. For low limits, however, it is doing a less than or equal to comparison.
LM81
www.national.com 31