ADT7467 Analog Devices, Inc., ADT7467 Datasheet - Page 67

• Manufacturer Part Number: ADT7467
• Description: Dbcool Remote Thermal Monitor And Fan Controller
• Manufacturer: Analog Devices, Inc.

Table 32. Register 0x55—TACH 1 Minimum High Byte (Power-On Default = 0xFF)
Bit
<4:0>
<7:5>
Table 33. PWM Configuration Registers
Register Address
0x5C
0x5D
0x5E
Bit
<2:0>
<3>
<4>
<7:5>
1
These registers become read-only registers when the Configuration Register 1 lock bit is set to 1. Any subsequent attempts to write to these registers fail.
Name
Reserved
SCADC
Name
SPIN
SLOW
INV
BHVR
R/W
Read only
Read/write
R/W
Read/write
Read/write
Read/write
R/W
Read/write
Read/write
Read/write
Read/write
1
Description
These bits are reserved when Bit 6 of Configuration 2 Register (0x73) is set (single-channel
ADC mode). Otherwise, these bits represent Bits <4:0> of the TACH1 minimum high byte.
When Bit 6 of Configuration 2 Register (0x73) is set (single-channel ADC mode), these bits
are used to select the only channel from which the ADC makes measurements. Otherwise,
these bits represent Bits <7:5> of the TACH1 minimum high byte.
Description
PWM1 configuration.
PWM2 configuration.
PWM3 configuration.
Description
These bits control the start-up timeout for PWMx. The PWM output stays high until two
valid TACH rising edges are seen from the fan. If there is not a valid TACH signal during the
fan TACH measurement immediately after the fan start-up timeout period, the TACH
measurement reads 0xFFFF and Status Register 2 reflects the fan fault. If the TACH minimum
high and low bytes contain 0xFFFF or 0x0000, the Status Register 2 bit is not set, even if the
fan has not started.
000 = No start-up timeout
001 = 100 ms
010 = 250 ms (default)
011 = 400 ms
100 = 667 ms
101 = 1 sec
110 = 2 sec
111 = 4 sec
SLOW = 1 makes the ramp rates for acoustic enhancement four times longer.
This bit inverts the PWM output. The default is 0, which corresponds to a logic high
output for 100% duty cycle. Setting this bit to 1 inverts the PWM output so that 100%
duty cycle corresponds to a logic low output.
These bits assign each fan to a particular temperature sensor for localized cooling.
000 = Remote 1 temperature controls PWMx (automatic fan control mode).
001 = local temperature controls PWMx (automatic fan control mode).
010 = Remote 2 temperature controls PWMx (automatic fan control mode).
011 = PWMx runs at full speed.
100 = PWMx disabled (default).
101 = fastest speed calculated by local and Remote 2 temperature controls PWMx.
110 = fastest speed calculated by all three temperature channel controls PWMx.
111 = manual mode. PWM duty cycle registers (Reg. 0x30 to Reg. 0x32) become writable.
Rev. A | Page 67 of 80
Power-On Default
0x82
0x82
0x82
ADT7467