REV. C

ADT7463

–35–

Table VIII. Current PWM Duty Cycle Registers (Power-On Default = 0xFF)

Register Address

R/W

Description

0x30

Read/Write

PWM1 Current Duty Cycle (0% to 100% Duty Cycle = 0x00 to 0xFF)

0x31

Read/Write

PWM2 Current Duty Cycle (0% to 100% Duty Cycle = 0x00 to 0xFF)

0x32

Read/Write

PWM3 Current Duty Cycle (0% to 100% Duty Cycle = 0x00 to 0xFF)

These registers reflect the PWM duty cycle driving each fan at any given time. When in automatic fan speed control mode, the ADT7463 reports the PWM

duty cycles back through these registers. The PWM duty cycle values vary according to temperature in automatic fan speed control mode. During fan startup,

these registers report back 0x00. In software mode, the PWM duty cycle outputs can be set to any duty cycle value by writing to these registers.

Table IX. Operating Point Registers (Power-On Default = 0x64)

Register Address

R/W*

Description

0x33

Read/Write

Remote 1 Operating Point Register (Default = 100�C)

0x34

Read/Write

Local Temp Operating Point Register (Default = 100�C)

0x35

Read/Write

Remote 2 Operating Point Register (Default = 100�C)

The fans being controlled adjust to maintain temperature about an operating point.

*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.

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