Datasheet

ADT7470 Data Sheet
Rev. E | Page 32 of 40
Table 34. Register 0x43. Fan Pulses per Revolution Register (Power-On Default = 0x55).
Bit Name Read/Write Description
[1:0] Fan 1 Read/Write Sets the number of pulses to be counted when measuring Fan 1 speed.
Can be used to determine fan’s pulses per revolution number for unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
[3:2] Fan 2 Read/Write Sets the number of pulses to be counted when measuring Fan 2 speed.
Can be used to determine fan’s pulses per revolution number for unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
[5:4] Fan 3 Read/Write Sets the number of pulses to be counted when measuring Fan 3 speed.
Can be used to determine fan’s pulses per revolution for unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
[7:6] Fan 4 Read/Write Sets the number of pulses to be counted when measuring Fan 4 speed. Can be used to determine fan’s
pulses per revolution for unknown fan type.
Pulses Counted
00 = 1
01 = 2 (default)
10 = 3
11 = 4
Table 35. Register 0x44 to Register 0x57. Temperature Limit Registers.
Register Address Read/Write Description Power-On Default
0x44 Read/Write Temperature 1 low limit 0x81
0x45 Read/Write Temperature 1 high limit 0x7F
0x46 Read/Write Temperature 2 low limit 0x81
0x47 Read/Write Temperature 2 high limit 0x7F
0x48 Read/Write Temperature 3 low limit 0x81
0x49 Read/Write Temperature 3 high limit 0x7F
0x4A Read/Write Temperature 4 low limit 0x81
0x4B Read/Write Temperature 4 high limit 0x7F
0x4C Read/Write Temperature 5 low limit 0x81
0x4D Read/Write Temperature 5 high limit 0x7F
0x4E Read/Write Temperature 6 low limit 0x81
0x4F Read/Write Temperature 6 high limit 0x7F
0x50 Read/Write Temperature 7 low limit 0x81
0x51
Read/Write
Temperature 7 high limit
0x7F
0x52 Read/Write Temperature 8 low limit 0x81
0x53 Read/Write Temperature 8 high limit 0x7F
0x54 Read/Write Temperature 9 low limit 0x81
0x55 Read/Write Temperature 9 high limit 0x7F
0x56
Read/Write
Temperature 10 low limit
0x81
0x57 Read/Write Temperature 10 high limit 0x7F
Exceeding any of the temperature limits shown in Table 35 by 1°C causes the appropriate status bit to be set in the interrupt status registers.
High limits: An interrupt is generated when a value exceeds its high limit (> comparison).
Low limits: An interrupt is generated when a value is equal to or below its low limit (≤ comparison).