EVAL-ADT7463EB ON Semiconductor, EVAL-ADT7463EB Datasheet - Page 34

• Manufacturer Part Number: EVAL-ADT7463EB
• Manufacturer: ON Semiconductor

Specifications of EVAL-ADT7463EB

• Lead Free Status / RoHS Status: Supplier Unconfirmed

ADT7463
Register Address
0x20
0x21
0x22
0x23
0x24
If the extended resolution bits of these readings are also being read, the extended resolution registers (Reg. 0x76, 0x77) should be read first. Once the extended
resolution registers get read, the associated MSB reading registers get frozen until read. Both the extended resolution registers and the MSB registers get frozen.
Register Address
0x25
0x26
0x27
These temperature readings are in twos complement format.
*Note that a reading of 0x80 in a temperature reading register indicates a diode fault (open or short) on that channel. If the extended resolution bits of these readings
Register Address
0x28
0x29
0x2A
0x2B
0x2C
0x2D
0x2E
0x2F
These registers count the number of 11.11 µs periods (based on an internal 90 kHz clock) that occur between a number of consecutive fan TACH pulses (default = 2).
The number of TACH pulses used to count can be changed using the fan pulses per revolution register (Reg. 0x7B). This allows the fan speed to be accurately mea-
sured. Since a valid fan tachometer reading requires that two bytes are read, the low byte MUST be read first. Both the low and high bytes are then frozen until read.
At power-on, these registers contain 0x0000 until such time as the first valid fan TACH measurement is read in to these registers. This prevents false interrupts from
occurring while the fans are spinning up.
A count of 0xFFFF indicates that a fan is:
are also being read, the extended resolution registers (Reg. 0x76, 0x77) should be read first. Once the extended resolution registers get read, all associated MSB read-
ing registers get frozen until read. Both the extended resolution registers and the MSB registers get frozen.
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
Read-Only
R/W
R/W
R/W
Table VII. Fan Tachometer Reading Registers (Power-On Default = 0x00)
Table VI. Temperature Reading Registers (Power-On Default = 0x80)
Table V. Voltage Reading Registers (Power-On Default = 0x00)
2.5 V Reading (8 MSBs of reading)
5 V Reading (8 MSBs of reading)
12 V Reading (8 MSBs of reading)
Remote 1 Temperature Reading* (8 MSBs of reading)
Local Temperature Reading (8 MSBs of reading)
Remote 2 Temperature Reading* (8 MSBs of reading)
TACH1 Low Byte
TACH1 High Byte
TACH2 Low Byte
TACH2 High Byte
TACH3 Low Byte
TACH3 High Byte
TACH4 Low Byte
TACH4 High Byte
Description
V
V
Description
Description
CCP
CC
Reading: measures V
1. Stalled or blocked (object jamming the fan).
2. Failed (internal circuitry destroyed).
3. Not populated (the ADT7463 expects to see a fan connected to
4. Alternate function, e.g., TACH4 reconfigured as THERM pin.
5. 2-Wire Instead of 3-Wire Fan.
Reading: holds processor core voltage measurement (8 MSBs of reading)
each TACH. If a fan is not connected to that TACH, its TACH
minimum high and low byte should be set to 0xFFFF).
–34–
CC
through the V
CC
pin (8 MSBs of reading)
REV. C