Register

0x[HEX]

Register Name

DATA BITS

D7

D6

D5

D4

D3

D2

D1

D0

4D

PWM Frequency

0

0

0

PWMF4

PWMF3

PWMF2

PWMF1

PWMF0

4E

[Reserved]

Not Used

4F

Lookup Table Hystersis

0

0

0

LOOKH4

LOOKH3

LOOKH2

LOOKH1

LOOKH0

50–5F

Lookup Table

Lookup Table of up to 8 PWM and Temp Pairs in 8-bit Registers

60–BE

[Reserved]

Not Used

BF

Rmt Diode Temp Filter

0

0

0

0

0

RDTF1

RDTF0

ALTCOMP

C0–FD

[Reserved]

Not Used

FE

Manufacturer’s ID

0

0

000001

FF

Stepping/Die Rev. ID

0

1

010001

2.2 LM64 REGISTER MAP IN FUNCTIONAL ORDER

The following is a Register Map grouped in Functional Order. Some address locations have been left blank to maintain

compatibility with LM86. Addresses in parenthesis are mirrors of named address. Reading or writing either address will access

the same 8-bit register. The Fan Control and Configuration Registers are listed first, as there is a required order to setup these

registers first and then setup the others. The detailed explanations of each register will follow the order shown below. POR =

Power-On-Reset.

Register

[HEX]

Register Name

Read/Write

POR Default

[HEX]

FAN CONTROL REGISTERS

4A

PWM and RPM

R/W

20

4B

Fan Spin-Up Configuration

R/W

3F

4D

PWM Frequency

R/W

17

4C

PWM Value

Read Only

(R/W if Override Bit is Set)

00

50–5F

Lookup Table

R/W

See Table

4F

Lookup Table Hysteresis

R/W

04

CONFIGURATION REGISTER

03 (09)

Configuration

R/W

00

TACHOMETER COUNT AND LIMIT REGISTERS

46

Tach Count LSB

Read Only

N/A

47

Tach Count MSB

Read Only

N/A

48

Tach Limit LSB

R/W

FF

49

Tach Limit MSB

R/W

FF

LOCAL TEMPERATURE AND LOCAL SETPOINT REGISTERS

00

Local Temperature

Read Only

N/A

05 (0B)

Local High Setpoint

R/W

46 (70˚)

REMOTE DIODE TEMPERATURE AND SETPOINT REGISTERS

01

Remote Temperature MSB

Read Only

N/A

10

Remote Temperature LSB

Read Only

N/A

11

Remote Temperature Offset MSB

R/W

00

12

Remote Temperature Offset LSB

R/W

00

07 (0D)

Remote High Setpoint MSB

R/W

46 (70˚C)

13

Remote High Setpoint LSB

R/W

00

08 (0E)

Remote Low Setpoint MSB

R/W

00 (0˚C)

14

Remote Low Setpoint LSB

R/W

00

19

Remote TCRIT Setpoint

R/W

55 (85˚C)

21

Remote TCRIT Hys

R/W

0A (10˚C)

BF

Remote Diode Temperature Filter

R/W

00

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