ADM1030
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Table 17. VALUE AND LIMIT REGISTERS
Address Read/Write Description
0x06 Read/Only Extended Temperature Resolution (see Table 22).
0x08 Read/Write Fan Speed Reading − this register contains the fan speed tach measurement.
0x0A Read/Only Local Temperature Value − this register contains the 8 MSBs of the local temperature measurement.
0x0B Read/Only Remote Temperature Value − this register contains the 8 MSBs of the remote temperature reading.
0x0D Read/Write Local Temperature Offset − See Table 29.
0x0E Read/Write Remote Temperature Offset − See Table 30.
0x10 Read/Write Fan Tach High Limit − this register contains the limit for the fan tach measurement. Since the tach
circuit counts between pulses, a slow fan will result in a large measured value, so exceeding the limit
by one is the way to detect a slow or stalled fan. (Power-on Default = FFh)
0x14 Read/Write Local Temperature High Limit (Power-on Default 60rC).
0x15 Read/Write Local Temperature Low Limit (Power-on Default 0rC).
0x16 Read/Write Local Temperature Therm Limit (Power-on Default 70rC).
0x18 Read/Write Remote Temperature High Limit (Power-on Default 80rC).
0x19 Read/Write Remote Temperature Low Limit (Power-on Default 0rC).
0x1A Read/Write Remote Temperature Therm Limit (Power-on Default 100rC).
Table 18. REGISTER 0X00 CONFIGURATION REGISTER 1 POWER-ON DEFAULT 90H
Bit Name R/W Description
0 MONITOR Read/Write Setting this bit to a “1” enables monitoring of temperature and enables measurement of
the fan tach signals. (Power-up Default = 0)
1 INT Enable Read/Write Setting this bit to a “1” enables the INT output. 1 = Enabled 0 = Disabled (Power-up
Default = 0)
2 TACH/AIN Read/Write Clearing this bit to “0” selects digital fan speed measurement via the TACH pins. Setting
this bit to “1” configures the TACH pins as analog inputs that can measure the speed of
2-wire fans via a sense resistor. (Power-up Default = 0)
3 PWM Invert Read/Write Setting this bit to “1” inverts the PWM signal on the output pin. (Power-up Default = 0).
The power-up default makes the PWM_OUT pin go low for 100% duty cycle (suitable
for driving the fan using a PMOS device). Setting this bit to “1” makes the PWM_OUT
pin high for 100% duty cycle (intended for driving the fan using an NMOS device).
4 Fan Fault Enable Read/Write Logic 1 enables FAN_FAULT pin; Logic 0 disables FAN_FAULT output. (Power-up
Default = 1.)
6–5 PWM Mode Read/Write These two bits control the behavior of the fan in Auto Fan Speed Control Mode.
00 = Remote Temp controls Fan. (Program PWM duty cycle in Software Mode.)
11 = Fastest Calculated Speed Controls Fan. (Program RPM speed in Software Mode.)
7 Auto/SW Ctrl Read/Write Logic 1 selects Automatic Fan Speed Control; Logic 0 selects SW control. (Power-up
Default = 1) When under software control, PWM duty cycle or RPM values may be
programmed for the fan.
Table 19. REGISTER 0X01 CONFIGURATION 2 POWER-ON DEFAULT = 7FH
Bit Name R/W Description
0 PWM 1 En Read/Write Enables fan PWM output when this bit is a “1.”
1 Unused Read/Write Unused
2 TACH 1 En Read/Write Enables Tach input when set to “1.”
3 Unused
4 Loc Temp En Read/Write Enables Interrupts on Local Channel when set to “1.”
5 Remote Temp En Read/Write Enables Interrupts on Remote Channel when set to “1.” Default is normally enabled,
except when a diode fault is detected on power-up.
6 Unused Read/Write Unused
7 SW Reset Read/Write When set to “1,” resets the device. Self-clears. Power-up Default = 0.
