Datasheet
ADT7470 Data Sheet
Rev. E | Page 36 of 40
Table 44. Register 0x74. Configuration Register 2 (Power-On Default = 0x00).
Bit Name Read/Write Description
[7] SHDN Read/Write Shutdown/low current mode.
[6:4] FREQ Read/Write These bits control PWM1–PWM4 frequency when the fan drive is configured as a low
frequency drive.
Register 0x74[6:4] Register 0x40[6] = 1 Register 0x40[6] = 0
000 11.0 Hz 1.4 kHz
001 14.7 Hz 22.5 kHz
010 22.1 Hz 22.5 kHz
011 29.4 Hz 22.5 kHz
100 35.3 Hz 22.5 kHz
101 44.1 Hz 22.5 kHz
110 58.8 Hz 22.5 kHz
111 88.2 Hz 22.5 kHz
[3] T4_dis Read/Write Writing a 1 disables Tach 4 measurements.
[2] T3_dis Read/Write Writing a 1 disables Tach 3 measurements.
[1] T2_dis Read/Write Writing a 1 disables Tach 2 measurements.
[0] T1_dis Read/Write Writing a 1 disables Tach 1 measurements.
Table 45. Register 0x78. Max TMP05 Temperature (Power-On Default = 0x00).
Bit Name Read/Write Description
[7:0] TMP05_MAX Read-only This register indicates the maximum of all TMP05 temperatures.
Table 46. Register 0x7C. TMP05 Zone Select 1 (Power-On Default = 0x00).
Bit Name Read/Write Description
[7:4] zone_fan1[3:0] Read/Write These bits determine which temperature zone controls Fan 1.
zone_fan1[3:0] Description
0000 max_temperature from Register 0x78 controls Fan 1.
0001 Temperature 1 from Register 0x20 controls Fan 1.
0010 Temperature 2 from Register 0x21 controls Fan 1.
0011
Temperature 3 from Register 0x22 controls Fan 1.
0100 Temperature 4 from Register 0x23 controls Fan 1.
0101 Temperature 5 from Register 0x24 controls Fan 1.
0110 Temperature 6 from Register 0x25 controls Fan 1.
0111 Temperature 7 from Register 0x26 controls Fan 1.
1000 Temperature 8 from Register 0x27 controls Fan 1.
1001 Temperature 9 from Register 0x28 controls Fan 1.
1010 Temperature 10 from Register 0x29 controls Fan 1.
[3:0] zone_fan2[3:0] Read/Write These bits determine which temperature zone controls Fan 2.
zone_fan2[3:0] Description
0000 max_temperature from Register 0x78 controls Fan 2.
0001 Temperature 1 from Register 0x20 controls Fan 2.
0010
Temperature 2 from Register 0x21 controls Fan 2.
0011
Temperature 3 from Register 0x22 controls Fan 2.
0100 Temperature 4 from Register 0x23 controls Fan 2.
0101 Temperature 5 from Register 0x24 controls Fan 2.
0110 Temperature 6 from Register 0x25 controls Fan 2.
0111 Temperature 7 from Register 0x26 controls Fan 2.
1000 Temperature 8 from Register 0x27 controls Fan 2.
1001 Temperature 9 from Register 0x28 controls Fan 2.
1010 Temperature 10 from Register 0x29 controls Fan 2.