SNAS264D April   2006  – February 2024 LM94

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
    1. 3.1 Functional Block Diagram
  5. 4 Pin Configuration and Functions
    1. 4.1 Server Terminology
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Operating Ratings
    3.     11
    4. 5.3 DC Electrical Characteristics
    5. 5.4 AC Electrical Characteristics
    6.     14
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Feature Description
      1. 6.2.1  Monitoring Cycle Time
      2. 6.2.2  ΣΔ A/D Inherent Averaging
      3. 6.2.3  Temperature Monitoring
        1. 6.2.3.1 “Remote Diode” TruTherm Mode
        2. 6.2.3.2 Temperature Data Format
        3. 6.2.3.3 Thermal Diode Fault Status
      4. 6.2.4  Event Errors for Fan Boost
      5. 6.2.5  Voltage Monitoring
      6. 6.2.6  Recommended External Scaling Resistors for +12V Power Rails
      7. 6.2.7  Recommended External Scaling Circuit for −12V Power Input
      8. 6.2.8  Adding External Scaling Resistors to Other Analog Inputs
      9. 6.2.9  Dynamic Vccp Monitoring Using VID
      10. 6.2.10 Monitoring Analog Temperature Sensors
      11. 6.2.11 VREF Output
      12. 6.2.12 PROCHOT Background Information
      13. 6.2.13 PROCHOT Monitoring
      14. 6.2.14 PROCHOT Output Control
      15. 6.2.15 Fan Speed Measurement
      16. 6.2.16 Smart Fan Speed Measurement
      17. 6.2.17 Inputs/Outputs
        1. 6.2.17.1 ALERT Output
        2. 6.2.17.2 RESET Input/Output
        3. 6.2.17.3 PWM1 and PWM2 Outputs
        4. 6.2.17.4 VRD1_HOT and VRD2_HOT Inputs
        5. 6.2.17.5 GPIO and GPI PINS
        6. 6.2.17.6 Fan Tach Inputs
      18. 6.2.18 Fan Control
        1. 6.2.18.1 Automatic Fan Control Methods
        2. 6.2.18.2 LUT Fan Control Duty Cycles
        3. 6.2.18.3 Alternate LUT PWM Mapping
        4. 6.2.18.4 Fan Control Priorities
        5. 6.2.18.5 PWM to 100% Conditions
        6. 6.2.18.6 VRDx_HOT Ramp-Up/Ramp-Down
        7. 6.2.18.7 PROCHOT Ramp-Up/Ramp-Down
        8. 6.2.18.8 Manual PWM Override
        9. 6.2.18.9 Fan Spin-Up Control
      19. 6.2.19 XOR TREE TEST
    3. 6.3 Programming
      1. 6.3.1 SMBus Interface
        1. 6.3.1.1 SMBus ADDRESSING
        2. 6.3.1.2 DIGITAL NOISE EFFECT ON SMBus COMMUNICATION
        3. 6.3.1.3 GENERAL SMBus TIMING
        4. 6.3.1.4 SMBus ERROR SAFETY FEATURES
        5. 6.3.1.5 Serial Interface Protocols
          1. 6.3.1.5.1 Address Incrementing
          2. 6.3.1.5.2 Block Command Code Summary
          3. 6.3.1.5.3 Write Operations
            1. 6.3.1.5.3.1 Write Byte
            2. 6.3.1.5.3.2 Write Word
            3. 6.3.1.5.3.3 SMBus Write Block to Any Address
            4. 6.3.1.5.3.4 I2C Block Write
          4. 6.3.1.5.4 Read Operations
            1. 6.3.1.5.4.1 Read Byte
            2. 6.3.1.5.4.2 Read Word
            3. 6.3.1.5.4.3 SMBus Block-Write Block-Read Process Call
            4. 6.3.1.5.4.4 Simulated SMBus Block-Write Block-Read Process Call
            5. 6.3.1.5.4.5 SMBus Fixed Address Block Reads
            6. 6.3.1.5.4.6 I2C Block Reads
        6. 6.3.1.6 READING AND WRITING 16-BIT REGISTERS
    4. 6.4 Registers
      1. 6.4.1  Regsiter Warnings
      2. 6.4.2  Register Summary Table
      3. 6.4.3  Factory Registers 00h–04h
        1. 6.4.3.1 Register 00h XOR Test
        2. 6.4.3.2 Register 01h SMBus Test
        3. 6.4.3.3 “REMOTE DIODE” MODE SELECT
          1. 6.4.3.3.1 Register 05h Remote-Diode Transistor Mode Select
      4. 6.4.4  Value Registers Section 1
        1. 6.4.4.1 Registers 06-07h and 50–53h Unfiltered Temperature Value Registers
        2. 6.4.4.2 Registers 08–09h and 54–55h Filtered Temperature Value Registers
        3. 6.4.4.3 Register 0Ah and 0Bh PWM1 and PWM2 8-bit Duty Cycle Value
      5. 6.4.5  PWM Duty Cycle Overide Registers
        1. 6.4.5.1 Register 0Ch PWM1 Duty Cycle Override (low byte)
        2. 6.4.5.2 Register 0Dh PWM1 Duty Cycle Override (high byte)
        3. 6.4.5.3 Register 0Eh PWM2 Duty Cycle Override (low byte)
        4. 6.4.5.4 Register 0Fh PWM2 Duty Cycle Override (high byte)
      6. 6.4.6  Extended Resolution Value Registers
        1. 6.4.6.1 Registers 10h - 17h Zone 1 (CPU1) and Zone 2 (CPU2) Extended Resolution Unfiltered Temperature Value Registers, Most and Least Significant Bytes
        2. 6.4.6.2 Registers 18h – 1Fh Zone 1 (CPU1) and Zone 2 (CPU2) Extended Resolution Filtered Value Registers, Most and Least Significant Bytes
        3. 6.4.6.3 Registers 20h – 23h Zone 3 and Zone 4 Extended Resolution Value Registers, Most and Least Significant Bytes
      7. 6.4.7  PI Loop Fan Control Setup Registers
        1. 6.4.7.1  Register 31h Internal/External Temperature Source Select
        2. 6.4.7.2  Register 32h PWM Filter Settings
        3. 6.4.7.3  Register 33h PWM1 Filter Shutoff Threshold
        4. 6.4.7.4  Register 34h PWM2 Filter Shutoff Threshold
        5. 6.4.7.5  Register 35h PI/LUT Fan Control Bindings
        6. 6.4.7.6  Register 36h PI Controller Minimum PWM and Hysteresis
        7. 6.4.7.7  Registers 37h and 38h Zone 1 and 2 PI Controller Target Temperature (Tcontrol)
        8. 6.4.7.8  Register 39h and 3Ah Zone 1 and 2 PI Fan Control Off Temperature (Toff)
        9. 6.4.7.9  Register 3Bh Proportional Coefficient
        10. 6.4.7.10 Register 3Ch Integral Coefficient
        11. 6.4.7.11 Register 3Dh PI Coefficient Exponents
      8. 6.4.8  Device Identification Registers (3Eh-3Fh)
        1. 6.4.8.1 Register 3Eh Manufacturer ID
        2. 6.4.8.2 Register 3Fh Version/Stepping
      9. 6.4.9  BMC Error Status Registers 40h–47h
        1. 6.4.9.1 Register 40h B_Error Status 1
        2. 6.4.9.2 Register 41h B_Error Status 2
        3. 6.4.9.3 Register 42h B_Error Status 3
        4. 6.4.9.4 Register 43h B_Error Status 4
        5. 6.4.9.5 Register 44h B_ P1_PROCHOT Error Status
        6. 6.4.9.6 Register 45h  B_P2_PROCHOT Error Status
        7. 6.4.9.7 Register 46h B_GPI Error Status
        8. 6.4.9.8 Register 47h B_Fan Error Status
      10. 6.4.10 Host Error Status Registers
        1. 6.4.10.1 Register 48h H_Error Status 1
        2. 6.4.10.2 Register 49h H_Error Status 2
        3. 6.4.10.3 Register 4Ah H_Error Status 3
        4. 6.4.10.4 Register 4Bh H_Error Status 4
        5. 6.4.10.5 Register 4Ch  H_P1_PROCHOT Error Status
        6. 6.4.10.6 Register 4Dh  B_P2_PROCHOT Error Status
        7. 6.4.10.7 Register 4Eh H_GPI Error Status
        8. 6.4.10.8 Register 4Fh H_Fan Error Status
      11. 6.4.11 Value Registers
        1. 6.4.11.1  Registers 50–53h Unfiltered Temperature Value Registers
        2. 6.4.11.2  Registers 54–55h Filtered Temperature Value Registers
        3. 6.4.11.3  Register 56–65h A/D Channel Voltage Registers
        4. 6.4.11.4  Register 67h Current P1_PROCHOT
        5. 6.4.11.5  Register 68h Average P1_PROCHOT
        6. 6.4.11.6  Register 69h Current P2_PROCHOT
        7. 6.4.11.7  Register 6Ah Average P2_PROCHOT
        8. 6.4.11.8  Register 6Bh Current GPI State
        9. 6.4.11.9  Register 6Ch P1_VID
        10. 6.4.11.10 Register 6Dh P2_VID
        11. 6.4.11.11 Register 6E–75h Fan Tachometer Readings
      12. 6.4.12 Limit Registers
        1. 6.4.12.1 Registers 78–7Fh Temperature Limit Registers
        2. 6.4.12.2 Registers 80–83h Fan Boost Temperature Registers
        3. 6.4.12.3 Register 84h Zone1, and Zone2 Hysteresis for Limit Comparisons
        4. 6.4.12.4 Register 85h Zone3 and Zone4 Hysteresis for Limit Comparisons
        5. 6.4.12.5 Registers 8E–8Fh Zone 1b and Zone 2b Temperature Reading Adjustment Registers
        6. 6.4.12.6 Registers 90–AFh Voltage Limit Registers
        7. 6.4.12.7 Register B0–B1h  PROCHOT User Limit Registers
        8. 6.4.12.8 Register B2–B3h Dynamic Vccp Limit Offset Registers
        9. 6.4.12.9 Register B4–BBh Fan Tach Limit Registers
      13. 6.4.13 Setup Registers
        1. 6.4.13.1  Register BCh Special Function Control 1 (Voltage Hysteresis and Fan Control Filter Enable)
        2. 6.4.13.2  Register BDh Special Function Control 2 (Smart Tach Mode Enable, Fan Control Temperature Resolution Control and VID Mode Select)
        3. 6.4.13.3  Register BEh GPI/VID Level Control
        4. 6.4.13.4  Register BFh PWM Ramp Control
        5. 6.4.13.5  Register C0h Fan Boost Hysteresis (Zones 1/2)
        6. 6.4.13.6  Register C1h Fan Boost Hysteresis (Zones 3/4)
        7. 6.4.13.7  Register C2h Zones 1/2 Spike Smoothing Control
        8. 6.4.13.8  Register C3h LUT 1/2 MinPWM and Hysteresis
        9. 6.4.13.9  Register C4h LUT 3/4 MinPWM and Hysteresis
        10. 6.4.13.10 Register C5h GPO
        11. 6.4.13.11 Register C6h PROCHOT Control
        12. 6.4.13.12 Register C7h PROCHOT Time Interval
        13. 6.4.13.13 Register C8h PWM1 Control 1
        14. 6.4.13.14 Register C9h PWM1 Control 2
        15. 6.4.13.15 Register CAh PWM1 Control 3
        16. 6.4.13.16 Register CBh PWM1 Control 4
        17. 6.4.13.17 Register CCh PWM2 Control 1
        18. 6.4.13.18 Register CDh PWM2 Control 2
        19. 6.4.13.19 Register CEh PWM2 Control 3
        20. 6.4.13.20 Register CFh PWM2 Control 4
        21. 6.4.13.21 Register D0h–D3h LUT 1 to 4 Base Temperatures
        22. 6.4.13.22 Register D4h–DFh Lookup Table Steps—LUT 1/2 and LUT 3/4 Offset Temperature
        23. 6.4.13.23 Register E0h Special Function TACH to PWM Binding
        24. 6.4.13.24 Register E1h Tachometer Fan Boost Control Register
        25. 6.4.13.25 Register E2h LM94 Status Control
        26. 6.4.13.26 Register E3h LM94 Configuration
      14. 6.4.14 Sleep State Control and Mask Registers
        1. 6.4.14.1 Register E4h Sleep State Control
        2. 6.4.14.2 Register E5h S1 GPI Mask
        3. 6.4.14.3 Register E6h S1 Tach Mask
        4. 6.4.14.4 Register E7h S3 GPI Mask
        5. 6.4.14.5 Register E8h S3 Tach Mask
        6. 6.4.14.6 Register E9h S3 Temperature/Voltage Mask
        7. 6.4.14.7 Register EAh S4/5 GPI Mask
        8. 6.4.14.8 Register EBh S4/5 Temperature/Voltage Mask
      15. 6.4.15 Other Mask Registers
        1. 6.4.15.1 Register ECh GPI Error Mask
        2. 6.4.15.2 Register EDh Miscellaneous Error Mask
        3. 6.4.15.3 Register EE and EFh Zone 1a and Zone 2a Adjustment Register
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power On
      2. 7.1.2 Resets
      3. 7.1.3 Address Selection
      4. 7.1.4 Device Setup
      5. 7.1.5 Round Robin Voltage/Temperature Conversion Cycle
      6. 7.1.6 Error Status Registers
        1. 7.1.6.1 ASF Mode
      7. 7.1.7 Masking, Error Status and ALERT
      8. 7.1.8 Layout and Grounding
    2. 7.2 Typical Application
      1. 7.2.1 Thermal Diode Application
        1. 7.2.1.1 Diode Non-Ideality
          1. 7.2.1.1.1 Diode Non-Ideality Factor Effect on Accuracy
          2. 7.2.1.1.2 Calculating Total System Accuracy
          3. 7.2.1.1.3 Compensating for Different Non-Ideality
  9. 8 Layout
    1. 8.1 Recommended Implementation
    2. 8.2 PCB Layout for Minimizing Noise
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.4.2 Register Summary Table

Table 6-3 Register Key
Term Description
N/D Not Defined
N/A Not Applicable
R Read Only
R/W Read or Write
RWC Read or Write to Clear
Lock Register Name Address Default Description
FACTORY REGISTERS
x XOR Test 00h 00h Used to set the XOR test tree mode
SMBus Test 01h 00 SMBus read/write test register
Reserved 02h-04h N/D
“REMOTE DIODE” MODE SELECT
x Transistor Mode Select 05h 00h Selects Diode Mode (default) or Transistor Mode for “Remote Diode” measurements
VALUE REGISTER SECTION 1
Zone 1b (CPU1 Diode b) Temp 06h 00h Measured value of remote thermal diode temperature channel 1b
Zone 2b (CPU2 Diode b) Temp 07h 00h Measured value of remote thermal diode temperature channel 2b
Zone 1b (CPU1 Diode b) Filtered Temp 08h 00h Filtered value of remote thermal diode temperature channel 1b
Zone 2b (CPU2 Diode b) Fitlered Temp 09h 00h Filtered value of remote thermal diode temperature channel 2b
PWM1 8-bit Duty Cycle Value 0Ah 00h 8- bit value of the PWM1 duty cycle.
PWM2 8-bit Duty Cycle Value 0Bh 00h 8-bit value of the PWM2 duty cycle
HIGH RESOLUTION PWM OVERIDE REGISTERS
x PWM1 Duty Cycle Override (low byte) 0Ch 00h Lower byte of the high resolution PWM1 duty cycle register
x PWM1 Duty Cycle Override (high byte) 0Dh 00h Upper byte of the high resolution PWM1 duty cycle register
x PWM2 Duty Cycle Override (low byte) 0Eh 00h Lower byte of the high resolution PWM2 duty cycle register
x PWM2 Duty Cycle Override (high byte) 0Fh 00h Upper byte of the high resolution PWM2 duty cycle register
EXTENDED RESOLUTION TEMPERATURE VALUE REGISTERS
Z1a_LSB 10h 00h Zone 1a (CPU1) extended resolution unfiltered temperature value register, least-significant byte
Z1a_MSB 11h 00h Zone 1a (CPU1) extended resolution unfiltered temperature value register, most-significant byte
Z1b_LSB 12h 00h Zone 1b (CPU1) extended resolution unfiltered temperature value register, least-significant-byte
Z1b_MSB 13h 00h Zone 1b (CPU1) extended resolution unfiltered temperature value register, most-significant byte
Z2a_LSB 14h 00h Zone 2a (CPU2) extended resolution unfiltered temperature value register, least-significant-byte
Z2a_MSB 15h 00h Zone 2a (CPU2) extended resolution unfiltered temperature value register, most-significant byte
Z2b_LSB 16h 00h Zone 2b (CPU2) extended resolution unfiltered temperature value register, least-significant-byte
Z2b_MSB 17h 00h Zone 2b (CPU2) extended resolution unfiltered temperature value register, most-significant byte
Z1a_F_LSB 18h 00h Zone 1a (CPU1) extended resolution filtered temperature value register, least-significant byte
Z1a_F_MSB 19h 00h Zone 1a (CPU1) extended resolution filtered temperature value register, most-significant byte
Z1b_F_LSB 1Ah 00h Zone 1b (CPU1) extended resolution filtered temperature value register, least-significant-byte
Z1b_F_MSB 1Bh 00h Zone 1b (CPU1) extended resolution filtered temperature value register, most-significant byte
Z2a_F_LSB 1Ch 00h Zone 2a (CPU2) extended resolution filtered temperature value register, least-significant-byte
Z2a_F_MSB 1Dh 00h Zone 2a (CPU2) extended resolution filtered temperature value register, most-significant byte
Z2b_F_LSB 1Eh 00h Zone 2b (CPU2) extended resolution filtered temperature value register, least-significant-byte
Z2b_F_MSB 1Fh 00h Zone 2b (CPU2) extended resolution filtered temperature value register, most-significant byte
Z3_LSB 20h 00h Zone 3 (Internal) extended resolution temperature value register, least-significant byte
Z3_MSB 21h 00h Zone 3 (Internal) extended resolution temperature value register, least-significant byte
Z4_LSB 22h 00h Zone 4 (External Digital) extended resolution temperature value register, most-significant byte
Z4_MSB 23h 00h Zone 4 (External Digital) extended resolution temperature value register, least-significant byte
  
Reserved 24h-30h N/D
 
PI LOOP AND FAN CONTROL SETUP REGISTERS
x Temperature Source Select 31h 00h Selects the temperature source for some temperature zones.
x PWM Filter Settings 32h 00h Sets the IIR filter coefficients for the PWM outputs for low resolution sources
x PWM1 Filter Shutoff Threshold 33h 00h PWM1 Filter Shutoff Threshold
x PWM2 Filter Shutoff Threshold 34h 00h PWM2 Filter Shutoff Threshold
x PI/LUT Fan Control Bindings 35h 30h PI/LUT fan control binding configuration
x PI Controller Minimum PWM and Hysteresis 36h 00h PI Controller Minimum PWM and Hysteresis settings
x Zone 1 Tcontrol 37h 00h Zone 1 (CPU1) PI Controller Target Temperature (Tcontrol)
x Zone 2 Tcontrol 38h 00h Zone 2 (CPU2) PI Controller Target Temperature (Tcontrol)
x Zone 1 Toff 39h 80h Zone 1 (CPU1) PI Controller Off Temperature (Toff)
x Zone 2 Toff 3Ah 80h Zone 2 (CPU2) PI Controller Off Temperature (Toff)
x P Coefficient 3Bh 00h PI controller proportional coefficient
x I Coefficient 3Ch 00h PI controller integral coefficient
x PI Exponents 3Dh 00h PI controller coefficient exponents
DEVICE IDENTIFICATION REGISTERS
Manufacturer ID 3Eh 01h Contains manufacturer ID code
Version/Stepping 3Fh 79h Contains code for major and minor revisions
BMC ERROR STATUS REGISTERS
B_Error Status 1 40h 00h BMC error status register 1
B_Error Status 2 41h 00h BMC error register 2
B_Error Status 3 42h 00h BMC error register 3
B_Error Status 4 43h 00h BMC error register 4
B_ P1_PROCHOT Error Status 44h 00h BMC error register for P1_PROCHOT
B_ P2_PROCHOT Error Status 45h 00h BMC error register for P2_PROCHOT
B_GPI Error Status 46h 00h BMC error register for GPIs
B_Fan Error Status 47h 00h BMC error register for Fans
HOST ERROR STATUS REGISTERS
H_Error Status 1 48h 00h HOST error status register 1
H_Error Status 2 49h 00h HOST error register 2
H_Error Status 3 4Ah 00h HOST error register 3
H_Error Status 4 4Bh 00h HOST error register 4
H_ P1_PROCHOT Error Status 4Ch 00h HOST error register for P1_PROCHOT
H_ P2_PROCHOT Error Status 4Dh 00h HOST error register for P2_PROCHOT
H_GPI Error Status 4Eh 00h HOST error register for GPIs
H_Fan Error Status 4Fh 00h HOST error register for Fans
VALUE REGISTERS SECTION 2
Zone 1a (CPU1) Temp 50h 00h Measured value of remote thermal diode temperature channel 1a
Zone 2a (CPU2) Temp 51h 00h Measured value of remote thermal diode temperature channel 2a
Zone 3 (Internal) Temp 52h 00h Measured temperature from on-chip sensor
Zone 4 (External Digital) Temp 53h 00h Measured temperature from external temperature sensor
Zone 1a (CPU1) Filtered Temp 54h 00h Filtered value of remote thermal diode temperature channel 1a
Zone 2a (CPU2) Filtered Temp 55h 00h Filtered value of remote thermal diode temperature channel 2a
AD_IN1 Voltage 56h N/D Measured value of AD_IN1
AD_IN2 Voltage 57h N/D Measured value of AD_IN2
AD_IN3 Voltage 58h N/D Measured value of AD_IN3
AD_IN4 Voltage 59h N/D Measured value of AD_IN4
AD_IN5 Voltage 5Ah N/D Measured value of AD_IN5
AD_IN6 Voltage 5Bh N/D Measured value of AD_IN6
AD_IN7 Voltage 5Ch N/D Measured value of AD_IN7
AD_IN8 Voltage 5Dh N/D Measured value of AD_IN8
AD_IN9 Voltage 5Eh N/D Measured value of AD_IN9
AD_IN10 Voltage 5Fh N/D Measured value of AD_IN10
AD_IN11 Voltage 60h N/D Measured value of AD_IN11
AD_IN12 Voltage 61h N/D Measured value of AD_IN12
AD_IN13 Voltage 62h N/D Measured value of AD_IN13
AD_IN14 Voltage 63h N/D Measured value of AD_IN14
AD_IN15 Voltage 64h N/D Measured value of AD_IN15
AD_IN16 Voltage 65h N/D Measured value of AD_IN16 (VDD 3.3V S/B)
 
Reserved 66h N/D
 
Current P1_PROCHOT 67h 00h Measured P1_PROCHOT throttle percentage
Average P1_PROCHOT 68h 00h Average P1_PROCHOT throttle percentage
Current P2_PROCHOT 69h 00h Measured P2_PROCHOT throttle percentage
Average P2_PROCHOT 6Ah 00h Average P2_PROCHOT throttle percentage
 
GPI State 6Bh 00h Current GPIO state
 
P1_VID 6Ch 00h Current VID value of Processor 1
P2_VID 6Dh 00h Current VID value of Processor 2
 
FAN Tach 1 LSB 6Eh 00h Measured FAN Tach 1 LSB
FAN Tach 1 MSB 6Fh 00h Measured FAN Tach 1 MSB
FAN Tach 2 LSB 70h 00h Measured FAN Tach 2 LSB
FAN Tach 2 MSB 71h 00h Measured FAN Tach 2 MSB
FAN Tach 3 LSB 72h 00h Measured FAN Tach 3 LSB
FAN Tach 3 MSB 73h 00h Measured FAN Tach 3 MSB
FAN Tach 4 LSB 74h 00h Measured FAN Tach 4 LSB
FAN Tach 4 MSB 75h 00h Measured FAN Tach 4 MSB
 
Reserved 76h-77h N/D
 
TEMPERATURE LIMIT REGISTERS
Zone 1 (CPU1) Low Temp 78h 80h Low limit for external thermal diode temperature channel 1 (D1) measurement
Zone 1 (CPU1) High Temp 79h 80h High limit for external thermal diode temperature channel 1 (D1) measurement
Zone 2 (CPU2) Low Temp 7Ah 80h Low limit for external thermal diode temperature channel 2 (D2) measurement
Zone 2 (CPU2) High Temp 7Bh 80h High limit for external thermal diode temperature channel 2 (D2) measurement
Zone 3 (Internal) Low Temp 7Ch 80h Low limit for local temperature measurement
Zone 3 (Internal) High Temp 7Dh 80h High limit for local temperature measurement
Zone 4 (External Digital) Low Temp 7Eh 80h Low limit for external digital temperature sensor
Zone 4 (External Digital) High Temp 7Fh 80h High limit for external digital temperature sensor
 
x Fan Boost Temp Zone 1 80h 3Ch Zone 1 (CPU1) fan boost temperature
x Fan Boost Temp Zone 2 81h 3Ch Zone 2 (CPU2) fan boost temperature
x Fan Boost Temp Zone 3 82h 23h Zone 3 (Internal) fan boost temperature
x Fan Boost Temp Zone 4 83h 23h Zone 4 (External Digital) fan boost temperature
Zone1 and Zone 2 Hysteresis 84h 00h Zone 1 and Zone 2 hysteresis for limit comparisons
Zone 3 and Zone 4 Hysteresis 85h 00h Zone 3 and Zone 4 hysteresis for limit comparisons
 
Reserved 86h-8Dh N/D
 
ZONE 1b and 2b TEMPERATURE READING ADJUSTMENT REGISTERS
Zone 1b Temp Adjust 8Eh 00h Allows all Zone 1b temperature measurements to be adjusted by a programmable offset.
Zone 2b Temp Adjust 8Fh 00h Allows all Zone 2b temperature measurements to be adjusted by a programmable offset.
OTHER LIMIT REGISTERS
AD_IN1 Low Limit 90h 00h Low limit for analog input 1 measurement
AD_IN1 High Limit 91h FFh High limit for analog input 1 measurement
AD_IN2 Low Limit 92h 00h Low limit for analog input 2 measurement
AD_IN2 High Limit 93h FFh High limit for analog input 2 measurement
AD_IN3 Low Limit 94h 00h Low limit for analog input 3 measurement
AD_IN3 High Limit 95h FFh High limit for analog input 3 measurement
AD_IN4 Low Limit 96h 00h Low limit for analog input 4 measurement
AD_IN4 High Limit 97h FFh High limit for analog input 4 measurement
AD_IN5 Low Limit 98h 00h Low limit for analog input 5 measurement
AD_IN5 High Limit 99h FFh High limit for analog input 5 measurement
AD_IN6 Low Limit 9Ah 00h Low limit for analog input 6 measurement
AD_IN6 High Limit 9Bh FFh High limit for analog input 6 measurement
AD_IN7 Low Limit 9Ch 00h Low limit for analog input 7 measurement
AD_IN7 High Limit 9Dh FFh High limit for analog input 7 measurement
AD_IN8 Low Limit 9Eh 00h Low limit for analog input 8 measurement
AD_IN8 High Limit 9Fh FFh High limit for analog input 8 measurement
AD_IN9 Low Limit A0h 00h Low limit for analog input 9 measurement
AD_IN9 High Limit A1h FFh High limit for analog input 9 measurement
AD_IN10 Low Limit A2h 00h Low limit for analog input 10 measurement
AD_IN10 High Limit A3h FFh High limit for analog input 10 measurement
AD_IN11 Low Limit A4h 00h Low limit for analog input 11 measurement
AD_IN11 High Limit A5h FFh High limit for analog input 11 measurement
AD_IN12 Low Limit A6h 00h Low limit for analog input 12 measurement
AD_IN12 High Limit A7h FFh High limit for analog input 12 measurement
AD_IN13 Low Limit A8h 00h Low limit for analog input 13 measurement
AD_IN13 High Limit A9h FFh High limit for analog input 13 measurement
AD_IN14 Low Limit AAh 00h Low limit for analog input 14 measurement
AD_IN14 High Limit ABh FFh High limit for analog input 14 measurement
AD_IN15 Low Limit ACh 00h Low limit for analog input 15 measurement
AD_IN15 High Limit ADh FFh High limit for analog input 15 measurement
AD_IN16 Low Limit AEh 00h Low limit for analog input 16 measurement
AD_IN16 High Limit AFh FFh High limit for analog input 16 measurement
 
P1_PROCHOT User Limit B0h FFh User settable limit for P1_PROCHOT
P2_PROCHOT User Limit B1h FFh User settable limit for P2_PROCHOT
 
Vccp1 Limit Offsets B2h 17h VID offset values for window comparator for CPU1 Vccp (AD_IN7)
Vccp2 Limit Offsets B3h 17h VID offset values for window comparator for CPU2 Vccp (AD_IN8)
 
FAN Tach 1 Limit LSB B4h FCh FAN Tach 1 Limit LSB
FAN Tach 1 Limit MSB B5h FFh FAN Tach 1 Limit MSB
FAN Tach 2 Limit LSB B6h FCh FAN Tach 2 Limit LSB
FAN Tach 2 Limit MSB B7h FFh FAN Tach 2 Limit MSB
FAN Tach 3 Limit LSB B8h FCh FAN Tach 3 Limit LSB
FAN Tach 3 Limit MSB B9h FFh FAN Tach 3 Limit MSB
FAN Tach 4 Limit LSB BAh FCh FAN Tach 4 Limit LSB
FAN Tach 4 Limit MSB BBh FFh FAN Tach 4 Limit MSB
SETUP REGISTERS
Special Function Control 1 BCh 00h Controls the hysteresis for voltage limit comparisons. Also selects filtered or unfiltered temperature usage for temperature limit comparisons and fan control.
Special Function Control 2 BDh 00h Enables smart tach detection. Also selects 0.5°C or 1.0°C resolution for fan control.
x GPI / VID Level Control BEh 00h Control the input threshold levels for the P1_VIDx, P2_VIDx and GPIO_x inputs.
x PWM Ramp Control BFh 00h Controls the ramp rate of the PWM duty cycle when VRDx_HOT is asserted, as well as the ramp rate when PROCHOT exceeds the user threshold.
x Fan Boost Hysteresis (Zones 1/2) C0h 44h Fan Boost Hysteresis for zones 1 and 2
x Fan Boost Hysteresis (Zones 3/4) C1h 44h Fan Boost Hysteresis for zones 3 and 4
x Zones 1/2 Spike Smoothing Control C2h 00h Configures Spike Smoothing for zones 1 and 2
x LUT 1/2 MinPWM and Hysteresis C3h 00h Controls MinPWM and hysteresis setting for LUT 1 and 2 auto-fan control
x LUT 3/4 MinPWM and Hysteresis C4h 00h Controls MinPWM and hysteresis setting for LUT 3 and 4 auto-fan control
 
GPO C5h 00h Controls the output state of the GPIO pins
 
PROCHOT Control C6h 00h Controls assertion of P1_PROCHOT or P2_PROCHOT
PROCHOT Time Interval C7h 11h Configures the time window over which the PROCHOT inputs are measured
 
x PWM1 Control 1 C8h 00h Controls PWM control source bindings.
x PWM1 Control 2 C9h 00h Controls PWM override and output polarity
x PWM1 Control 3 CAh 00h Controls PWM spin-up duration and duty cycle
x PWM1 Control 4 CBh 00h Frequency control for PWM1.
 
x PWM2 Control 1 CCh 00h Controls PWM control source bindings.
x PWM2 Control 2 CDh 00h Controls PWM override and output polarity
x PWM2 Control 3 CEh 00h Controls PWM spin-up duration and duty cycle
x PWM2 Control 4 CFh 00h Frequency control for PWM2
 
x LUT 1 Base Temperature D0h 00h Base temperature to which look-up table offset is applied for LUT 1
x LUT 2 Base Temperature D1h 00h Base temperature to which look-up table offset is applied for LUT 2
x LUT 3 Base Temperature D2h 00h Base temperature to which look-up table offset is applied for LUT 3
x LUT 4 Base Temperature D3h 00h Base temperature to which look-up table offset is applied for LUT 4
 
x Step 2 Temp Offset D4h 00h Step 2 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 3 Temp Offset D5h 00h Step 3 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 4 Temp Offset D6h 00h Step 4 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 5 Temp Offset D7h 00h Step 5 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 6 Temp Offset D8h 00h Step 6 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 7 Temp Offset D9h 00h Step 7 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 8 Temp Offset DAh 00h Step 8 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 9 Temp Offset DBh 00h Step 9 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 10 Temp Offset DCh 00h Step 10 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 11 Temp Offset DDh 00h Step 11 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 12 Temp Offset DEh 00h Step 12 LUT 1/2 and LUT 3/4 Offset Temperatures
x Step 13 Temp Offset DFh 00h Step 13 LUT 1/2 and LUT 3/4 Offset Temperatures
 
TACH to PWM Binding E0h 00h Controls the tachometer input to PWM output binding
x Tach Boost Control E1h 3Fh Controls the fan boost function upon a tach error
 
x LM94 Status/Control E2h 00h Gives Master error status, ASF reset control and Max PWM control
x LM94 Configuration E3h 00h Configures various outputs and provides START bit
SLEEP STATE CONTROL AND MASK REGISTERS
Sleep State Control E4h 03h Used to communicate the system sleep state to the LM94
S1 GPI Mask E5h FFh Sleep state S1 GPI error mask register
S1 Fan Mask E6h 0Fh Sleep state S1 fan tach error mask register
S3 GPI Mask E7h FFh Sleep state S3 GPI error mask register
S3 Fan Mask E8h 0Fh Sleep state S3 fan tach error mask register
S3 Temperature/Voltage Mask E9h 07h Sleep state S3 temperature or voltage error mask register
S4/5 GPI Mask EAh FFh Sleep state S4/5 GPI error mask register
S4/5 Temperature/Voltage Mask EBh 07h Sleep state S4/5 temperature or voltage error mask register
OTHER MASK REGISTERS
GPI Error Mask ECh FFh Error mask register for GPI faults
Miscellaneous Error Mask EDh 3Fh Error mask register for VRDx_HOT, GPI, and dynamic Vccp limit checking.
 
ZONE 1a AND 2a TEMPERATURE READING ADJUSTMENT REGISTERS
Zone 1a Temp Adjust EEh 00h Allows all Zone 1a temperature measurements to be adjusted by a programmable offset
Zone 2a Temp Adjust EFh 00h Allows all Zone 2a temperature measurements to be adjusted by a programmable offset
BLOCK COMMANDS
Block Write Command F0h N/A SMBus Block Write Command Code
Block Read Command F1h N/A SMBus Block Write/Read Process call
Fixed Block 0 F2h N/A Fixed block code address 40h, size 8 bytes
Fixed Block 1 F3h N/A Fixed block code address 48h, size 8 bytes
Fixed Block 2 F4h N/A Fixed block code address 50h, size 6 bytes
Fixed Block 3 F5h N/A Fixed block code address 56h, size 16 bytes
Fixed Block 4 F6h N/A Fixed block code address 67h, size 4 bytes
Fixed Block 5 F7h N/A Fixed block code address 6Eh, size 8 bytes
Fixed Block 6 F8h N/A Fixed block code address 78h, size 12 bytes
Fixed Block 7 F9h N/A Fixed block code address 90h, size 32 bytes
Fixed Block 8 FAh N/A Fixed block code address B4h, size 8 bytes
Fixed Block 9 FBh N/A Fixed block code address C8h, size 8 bytes
Fixed Block 10 FCh N/A Fixed block code address D0h, size 16 bytes
Fixed Block 11 FDh N/A Fixed block code address E5h, size 9 bytes
 
Reserved FEh-FFh N/A Reserved for future commands