Table 3. command byte bit assignments – Rainbow Electronics MAX1669 User Manual
Page 11
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