Table 1. register functions – Rainbow Electronics MAX6641 User Manual
Page 6
MAX6641
SMBus-Compatible Temperature Monitor with
Automatic PWM Fan-Speed Controller
6
_______________________________________________________________________________________
READ/
WRITE
REGISTER
ADDRESS
POR
STATE
FUNCTION/
NAME
D7
D6
D5
D4
D3
D2
D1
D0
R
00h
0000 0000
Read remote
(external)
temperature
MSB
(+128
°C)
(+64
°C)
(+32
°C)
(+16
°C) (+8°C)
(+4
°C)
(+2
°C)
LSB
(+1
°C)
R
01h
0000 0000
Read local
(internal)
temperature
MSB
(+128
°C)
(+64
°C)
(+32
°C)
(+16
°C) (+8°C)
(+4
°C)
(+2
°C)
LSB
(+1
°C)
R/W
02h
0000 00xx
Configuration
byte
Reserved
set to 0
Reserved
set to 0
Timeout: 0 =
enabled, 1 =
disabled
Fan
PWM
invert
Min duty
cycle:
0 = 0%,
1 = fan-
start duty
cycle
Spin-up
disable
X
X
R/W
03h
0110 1110
Remote-diode
temperature
OT limit
MSB
(+128
°C)
(+64
°C)
(+32
°C)
(+16
°C) (+8°C)
(+4
°C)
(+2
°C)
LSB
(+1
°C)
R/W
04h
0101 0000
Local-diode
temperature
OT limit
MSB
(+128
°C)
(+64
°C)
(+32
°C)
(+16
°C) (+8°C)
(+4
°C)
(+2
°C)
LSB
(+1
°C)
R
05h
00xx xxxx
OT status
Remote 1
= fault
Local 1 =
fault
X
X
X
X
X
X
R/W
06h
00xx xxxx
OT mask
Remote 1
= masked
Local 1 =
masked
X
X
X
X
X
X
R/W
07h
0110 000x
(96 = 40%)
Fan-start duty
cycle
MSB
(128/240)
(64/240)
(32/240)
( 16/240) (8/240)
(4/240)
LSB
(2/240)
X
R/W
08h
1111 000x
(240 =
100%)
Fan maximum
duty cycle
MSB
(128/240)
(64/240)
(32/240)
( 16/240) (8/240)
(4/240)
LSB
(2/240)
X
R/W
09h
0000 000x
Fan target duty
cycle
MSB
(128/240)
(64/240)
(32/240)
( 16/240) (8/240)
(4/240)
LSB
(2/240)
X
R
0Ah
0000 000x
Fan
instantaneous
duty cycle
MSB
(128/240)
(64/240)
(32/240)
( 16/240) (8/240)
(4/240)
LSB
(2/240)
X
R/W
0Bh
0000 0000
Remote-diode
fan-start
temperature
MSB
(+128
°C)
(+64
°C)
(+32
°C)
(+16
°C) (+8°C)
(+4
°C)
(+2
°C)
LSB
(+1
°C)
Table 1. Register Functions