Rainbow Electronics MAX6616 - Manual (Page 14)

MAX6615/MAX6616
Dual-Channel Temperature Monitors and
Fan-Speed Controllers with Thermistor Inputs
14 ______________________________________________________________________________________
Table 3. Register Map (continued)
R/ W ADD
POR
STATE
FUNCTION D7 D6 D5 D4 D3 D2 D1 D0
R/ W 1Ch
0000
0000 Fan status
byte
1 = fan 1
failure
1 = fan 2
failure
1 =
disabled
fan 1
tach
1 =
disabled
fan 2 tach
1 =
measure
fan 1
when it is
full speed
1 =
measure
fan 2
when it is
full speed
1 = m ask
FAN_FAIL
p i n
1 = fan 1
fail sets
fan 2
100%
R 1Eh
0000
0000 Channel 1
temp LSBs
MSB
(1/2°C)
—
LSB
(1/8°C)
— — — — —
R 1Fh
0000
0000 Channel 2
temp LSBs
MSB
(1/2°C)
—
LSB
(1/8°C)
— — — — —
R FDh
0000
0001 Read device
revision
0 0 0 0 0 0 0 1
R FEh
0110
1000 Read device
ID
0 1 1 0 1 0 0 0
R FFh
0100
1101
Read
m anufactur er
ID
0 1 0 0 1 1 0 1
*GPIO0 POR values are set by PRESET.
Table 4. Configuration Byte Definition (02h)
BIT NAME
POR
STATE
FUNCTION
7 RUN/STANDBY 0 Set to zero for normal operation. Set to 1 to suspend conversions and PWM outputs.
6 POR 0 Set to 1 to perform reset of all device registers.
5 TIMEOUT 0
Set TIMEOUT to zero to enable SMBus timeout for prevention of bus lockup. Set to 1 to
disable this function.
4 FAN1 PWM INVERT 1
Set fan PWM invert to zero to force PWM1 low when the duty cycle is 100%. Set to 1 to
force PWM1 high when the duty cycle is 100%.
3 FAN2 PWM INVERT 1
Set fan PWM invert to zero to force PWM2 low when the duty cycle is 100%. Set to 1 to
force PWM2 high when the duty cycle is 100%.
2 MIN DUTY CYCLE 0
Set min duty cycle to zero for a 0% duty cycle when the measured temperature is below the
fan-temperature threshold in automatic mode. When the temperature equals the fan-
temperature threshold, the duty cycle is the value in the fan-start duty-cycle register, and it
increases with increasing temperature.
Set min duty cycle to 1 to force the PWM duty cycle to the value in the fan-start duty-cycle
register when the measured temperature is below the fan-temperature threshold. As the
temperature increases above the temperature threshold, the duty cycle increases as
programmed.
1
TEMPERATURE
SOURCE SELECT
0
Selects either local or remote 2 as the source for temperature channel 2 register data.
When D1 = 0, the MAX6615/MAX6616 measure remote 2 and when D1 = 1, the
MAX6615/MAX6616 measure the internal die temperature.
0 SPIN-UP DISABLE 0 Set spin-up disable to 1 to disable spin-up. Set to zero for normal fan spin-up.