Temperature Monitors and
PWM Fan Controllers
Register Summary (continued)
Addr(H)
0A
0B
0D
0E
10
14
15
16
18
19
1A
1B
1C
READ/WRITE POR STATE
DESCRIPTION
R
0001 1110 Local temperature data:
(30°C) This register contains the 8 MSBs of the local temperature measurement.
R
0001 1110 Remote temperature data:
(30°C) This register contains the 8 MSBs of the local temperature measurement.
Local temperature offset:
Bit 7: Sign bit; when zero, the offset value in bits [3:0] is added to the measured local
temperature reading. When this bit is 1, the offset value in bits [3:0] is subtracted
R/W
0000 0000
from the local temperature reading.
Bits [6:4] Unused. This bits normally reads back zeros.
Bits [3:0] Offset value. This is added to or subtracted from the measured local
temperature reading.
Remote temperature offset:
Bit 7: Sign bit: When 0, the offset value in bits [3:0] is added to the measured remote
temperature reading. When this bit is 1, the offset value in bits [3:0] is subtracted
R/W
0000 0000
from the remote temperature reading.
Bits [6:4] Unused: These bits normally read back zeros.
Bits [3:0] Offset value: This is added to or subtracted from the measured remote
temperature reading.
Fan tachometer high-limit register:
R/W
1111 1111 Contains the limit of the fan-speed measurement. It detects a stalled fan if the
measured fan-speed data (reg_08h; proportional to fan period) is larger than the limit.
R/W
0011 1100 Local temp high limit:
(60°C) Contains the local high-temperature interrupt limit.
R/W
0000 0000 Local temp low limit:
(0°C)
Contains the local low-temperature interrupt limit.
Local temp THERM limit:
R/W
0100 0110 Contains the local high-temperature limit for the THERM output. Default is +70°C for
(70°C) the MAX6663/MAX6664; CRIT0 and CRIT1 determine the default value for the
MAX6653 (see Table 1).
R/W
0101 0000 Remote temp high limit:
(80°C) Contains the remote high-temperature interrupt limit.
R/W
0000 0000 Remote temp low limit:
(0°C)
Contains the remote low-temperature interrupt limit.
Remote temp THERM limit:
R/W
0110 0100 Contains the remote high-temperature limit for the THERM output. Default is +100°C
(100°C) for the MAX6663/MAX6664; CRIT0 and CRIT1 determine the default value for the
MAX6653 (see Table 1).
Local temp shutdown limit:
R/W
0101 1111 Contains the local high-temperature limit for the SDL output. Default is +95°C for
(95°C) the MAX6663/MAX6664; CRIT0 and CRIT1 determine the default value for the
MAX6653 (see Table 1).
Remote temp shutdown limit:
R/W
0111 1101 Contains the remote high-temperature limit for the SDR output. Default is +125°C for
(125°C) the MAX6663/MAX6664; CRIT0 and CRIT1 determine the default value for the
MAX6653 (see Table 1).
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