DS1780

21 of 28

VALUE RAM (ADDRESS 0x15h - 0x3Dh) Table 10.15

ADDRESS <A7:A0>h

R/W

DESCRIPTION

20h

R

+2.5V Input Reading.

21h

R

22h

R

+3.3V Input Reading.

23h

R

+5V Input Reading.

24h

R

+12V Input Reading.

25h

R

26h

R

Reserved.

27h

R

Temperature reading (Most significant 8-bits).

28h

R

FAN1 reading: This location stores the number of counts of the

internal clock per revolution.

29h

R

FAN2 reading: This location stores the number of counts of the

internal clock per revolution.

2Ah

R/W

Reserved.

2Bh

R/W

+2.5V High Limit (Note 1, 2).

2Ch

R/W

+2.5V Low Limit (Note 2).

2Dh

R/W

2Eh

R/W

2Fh

R/W

+3.3V High Limit (Note 1, 2).

30h

R/W

+3.3V Low Limit (Note 2).

31h

R/W

+5V High Limit (Note 1, 2).

32h

R/W

+5V Low Limit (Note 2).

33h

R/W

+12V High Limit (Note 1, 2).

34h

R/W

+12V Low Limit (Note 2).

35h

R/W

+2.5V_Sense/Vccp2 High Limit (Note 1, 2).

36h

R/W

+2.5V_Sense/Vccp2 Low Limit (Note 2).

37h

Reserved.

38h

Reserved.

39h

R/W

Hot Temperature (High) Limit (Note 1).

3Ah

R/W

Hot Temperature Hysteresis (Low) Limit.

3Bh

R/W

FAN1 Fan Count Limit: It is the number of counts of the internal clock for the

Low Limit of the fan speed.

3Ch

R/W

FAN2 Fan Count Limit: It is the number of counts of the internal clock for the

Low Limit of the fan speed.

3Dh

Reserved.

3Eh

R

Company id number (Note 5).

3Fh

R

Stepping id number (Note 6).

NOTES:

1. Setting all 1s 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.

2. For the high limits of the voltages, the device is doing a greater than comparison. For the low limits,

however, it is doing a less than or equal comparison.

3. This register should only be used by the manufacturer for testing of the ASIC. Reading or writing to

this register during normal use may lead to erroneous events.