ADT7476A
www.onsemi.com
57
Table 65. PWM CONFIGURATION REGISTERS
(Note 1)
Register Address
R/W
Description
Power-On Default
0x5C
R/W
PWM1 Configuration
0x62
0x5D
R/W
PWM2 Configuration
0x62
0x5E
R/W
PWM3 Configuration
0x62
Bit No.
Name
R/W
Description
[2:0]
SPIN
R/W
These bits control the startup 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 directly after the fan startup timeout period, the TACH measurement
reads 0xFFFF and Interrupt Status Register 2 reflects the fan fault. If the TACH minimum
high and low bytes contain 0xFFFF or 0x0000, the Interrupt Status Register 2 bit is not set,
even if the fan has not started.
000 = No Startup Timeout
001 = 100 ms
010 = 250 ms (Default)
011 = 400 ms
100 = 667 ms
101 = 1 sec
110 = 2 sec
111 = 4 sec
[3]
RES
N/A
Reserved. Do not write to this bit.
[4]
INV
R/W
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 100% duty cycle
corresponds to a logic low output.
[7:5]
BHVR
R/W
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 Full Speed (Default)
100 = PWMx Disabled
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 Current Duty Cycle Registers (0x30 to 0x32) Become Writable
1. These registers become read-only when the Configuration Register 1 Lock bit is set to 1. Any subsequent attempts to write to these registers fail.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from