LM96000EVAL/NOPB National Semiconductor, LM96000EVAL/NOPB Datasheet - Page 14

• Manufacturer Part Number: LM96000EVAL/NOPB
• Description: BOARD EVALUATION LM96000
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of LM96000EVAL/NOPB

• Sensor Type: Temperature, Fan Controller
• Sensing Range: 0°C ~ 125°C
• Interface: SMBus (2-Wire/I²C)
• Sensitivity: ±1°C
• Voltage - Supply: 3 V ~ 3.6 V
• Embedded: No
• Utilized Ic / Part: LM96000
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM96000EVAL

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Register
Address
30h
31h
32h
Register
Address
3Eh
Register
Address
3Fh
4.4 Register 30-32h: 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.
4.5 Register 3Eh: Company ID
The company ID register contains the company identification number. For National Semiconductor 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
The four least significant bits of the Version/Stepping register [3.0] contain the current stepping of the LM96000 silicon. The four
most significant bits [7.4] reflect the LM96000 base device number when set to a value of 0110b. For the LM96000, this register
will read 01101000b (68h). Bit 3 of the stepping field is set to indicate that the LM96000 is a super-set of the LM85 family of products.
The register is used by application software to identify which device in the hardware monitor family of ASICs has been implemented
in the given system. Based on this information, software can determine which registers to read from and write to. Further, application
software may use the current stepping to implement work-arounds for bugs found in a specific silicon stepping.
This register is read only — a write to this register has no effect.
Read/
Write
R/W
R/W
R/W
Read/
Write
R
Read/
Write
R
Register
Name
Fan1 Current PWM Duty
Fan2 Current PWM Duty
Fan3 Current PWM Duty
Register
Name
Version/Stepping
Register
Name
Company ID
Current Duty
0.3922%
25.098%
50.196%
100%
0%
Bit 7
(MSB)
7
.
.
.
.
.
.
.
.
.
Bit 7
(MSB)
VER3
Bit 7
(MSB)
7
7
7
Bit 6
6
Bit 6
VER2
Value (Decimal)
128
255
14
Bit 6
6
6
6
64
Bit 5
5
0
1
.
.
.
.
.
.
.
.
.
Bit 5
VER1
Bit 5
5
5
5
Bit 4
4
Bit 4
VER0
Value (Hex)
Bit 4
4
4
4
Bit 3
3
00h
01h
40h
80h
FFh
Bit 3
STP3
.
.
.
.
.
.
.
.
.
Bit 3
3
3
3
Bit 2
2
Bit 2
STP2
Bit 2
2
2
2
Bit 1
1
Bit 1
STP1
Bit 1
1
1
1
Bit 0
(LSB)
0
Bit 0
(LSB)
STP0
Bit 0
(LSB)
0
0
0
Default
Value
01h
Default
Value
68h
Default
Value
N/A
N/A
N/A