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Table 3. command byte bit assignments – Rainbow Electronics MAX1669 User Manual

Page 11

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MAX1669

Fan Controller and Remote Temperature Sensor

with SMBus Serial Interface

______________________________________________________________________________________

11

REGISTER

COMMAND

FUNCTION

00h

Reserved for future use

N/A

RTEMP

01h

Read latest temperature

N/A

RSTAT

02h

Read status byte (temp flags, I/O_ states)

N/A

RCFG

03h

Read configuration byte

0000 0010b

04h

Reserved for future use

N/A

05h

Reserved for future use

N/A

06h

Reserved for future use

N/A

RHI

07h

Read T

HIGH

limit

0111 1111b

RLOW

08h

Read T

LOW

limit

1100 1001b

WCFG

09h

Write configuration byte

N/A

0Ah

Reserved for future use

N/A

0Bh

Reserved for future use

N/A

0Ch

Reserved for future use

N/A

WHI

0Dh

Write T

HIGH

limit

N/A

WLOW

0Eh

Write T

LOW

limit

N/A

OSHT

0Fh

One-shot command. Will execute a single conversion even if the
device is in software standby.

N/A

RCRIT

10h

Read T

CRIT

limit

0110 0100b

RPROT

11h

Read write-once protection byte

0000 0000b

RFREQ

12h

Read PWM frequency

0000 0000b

RDUTY

13h

Read FAN duty factor

0000 0000b

RGPIO

14h

Read GPIO data

1100 0000b

15h

Reserved for future use

N/A

16h

Reserved for future use

N/A

17h

Reserved for future use

N/A

WCRIT

POR STATE

18h

Write T

CRIT

limit

N/A

WPROT

19h

Write write-once protection byte

N/A

WFREQ

1Ah

Write PWM frequency

N/A

WDUTY

1Bh

Write FAN duty factor

N/A

WGPIO

1Ch

Write GPIO data

N/A

RFU

1Dh-FDh

Reserved for future use

N/A

MFG ID

FEh

Manufacturing ID code = 4Dh, ASCII code for “M” (for Maxim)

Least Sig Byte

0100 1101b

DEV ID

FFh

Device ID code, specific to MAX1669

Least Sig Byte

0000 0101b

Table 3. Command Byte Bit Assignments

ID Codes