ADT7475 Analog Devices, Inc., ADT7475 Datasheet - Page 63

• Manufacturer Part Number: ADT7475
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

Table 53. Register 0x7B—TACH Pulses per Revolution Register (Power-On Default = 0x55)
Bit
[1:0]
[3:2]
[5:4]
[7:6]
Table 54. Register 0x7C—Configuration Register 5 (Power-On Default = 0x01)
Bit
[0]
[1]
[2]
[3]
[4]
[5]
Name
FAN1
FAN2
FAN3
FAN4
Name
TWOS
COMPL
TempOffset
GPIOD
GPIOP
RES
R1
T HERM
A
E
E A
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
1
Description
Twos complement = 1, sets the temperature range to twos complement temperature range.
Twos complement = 0, changes the temperature range to Offset 64. When this bit is changed, the
ADT7475 interprets all relevant temperature register values as defined by this bit.
TempOffset = 0, sets offset range to −63°C to +64°C with 0.5°C resolution.
TempOffset = 1, sets offset range to −63°C to +127°C with 1°C resolution.
These settings apply to the 0x70, 0x71, and 0x72 registers (Remote 1, local, and Remote 2 temperature
offset registers).
GPIO direction. When the GPIO function is enabled, this determines whether the GPIO is an input (0)
or an output (1).
GPIO polarity. When the GPIO function is enabled and is programmed as an output, this bit
determines whether the GPIO is active low (0) or high (1).
Reserved.
R1
T HERM
A
Description
Sets the number of pulses to be counted when measuring Fan 1 speed. Can be used to determine
fan pulses per revolution for an unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
Sets the number of pulses to be counted when measuring Fan 2 speed. Can be used to determine
fan pulses per revolution for an unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
Sets the number of pulses to be counted when measuring Fan 3 speed. Can be used to determine
fan pulses per revolution for an unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
Sets the number of pulses to be counted when measuring Fan 4 speed. Can be used to determine
fan pulses per revolution for an unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
T HERM
A
In offset 64 mode, writing −64°C to the appropriate
In twos complement mode, writing −128°C to the appropriate
E
E A
can also be disabled on any channel by the following:
E
E A
= 0 ,
T HERM
A
E
E A
temperature limit functionality is enabled for the Remote 1 temperature channel.
Rev. B | Page 63 of 68
T HERM
A
E
E A
temperature limit.
T HERM
A
E
E A
temperature limit.
ADT7475