Datasheet

LM96000

SNAS234C –APRIL 2004–REVISED MARCH 2013

www.ti.com

4.4 Register 30-32h: Current PWM Duty

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

Address Write Name (MSB) (LSB) Value

30h R/W Fan1 7 6 5 4 3 2 1 0 N/A

Current

PWM

Duty

31h R/W Fan2 7 6 5 4 3 2 1 0 N/A

Current

PWM

Duty

32h R/W Fan3 7 6 5 4 3 2 1 0 N/A

Current

PWM

Duty

The Current PWM Duty registers store the current duty cycle at each PWM output. At initial power-on, the PWM

duty cycle is 100% and thus, when read, this register will return FFh. After the Ready/Lock/Start/Override register

Start bit is set, this register and the PWM signals will be updated based on the algorithm described in the Auto

Fan Control Operating Mode section.

When read, the Current PWM Duty registers return the current PWM duty cycle. These registers are read only

unless the fan is in manual (test) mode, in which case a write to these registers will directly control the PWM duty

cycle for each fan. The PWM duty cycle is represented as shown in the following table.

Current Duty Value (Decimal) Value (Hex)

0% 0 00h

0.3922% 1 01h

. . .

25.098% 64 40h

. . .

50.196% 128 80h

. . .

100% 255 FFh

4.5 Register 3Eh: Company ID

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

Address Write Name (MSB) (LSB) Value

3Eh R Company 7 6 5 4 3 2 1 0 01h

The company ID register contains the company identification number. For Texas Instruments this is 01h. This

number is assigned by Intel and is a method for uniquely identifying the part manufacturer. This register is read

only — a write to this register has no effect.

4.6 Register 3Fh: Version/Stepping

Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1

Address Write Name (MSB) (LSB) Value

3Fh R Version/S VER3 VER2 VER1 VER0 STP3 STP2 STP1 STP0 68h

tepping

Product Folder Links: LM96000