RPM-Based Fan Controller with Multiple Temperature Zones & Hardware Thermal Shutdown
Datasheet
7.18
PWM Driver Configuration Register
Table 7.25 PWM Driver Configuration Register
ADDR
2Ah
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
PWM Driver
Config
PWM_
OT
R/W
-
-
-
-
-
-
POLARITY
00h
The PWM Driver Configuration Register controls the output type and polarity of the PWM fan drive
output.
Bit 4 - PWM_OT - Determines the output type for the PWM pin.
‘0’ (default) - The PWM pin is configured as an open drain output.
‘1’ - The PWM pin is configured as a push-pull output.
Bit 0 - POLARITY - Determines the polarity of the PWM pin.
‘0’ (default) - the Polarity of the PWM output driver is normal. A drive setting of 00h will cause the
output to be set at 0% duty cycle and a drive setting of FFh will cause the output to be set at 100%
duty cycle.
‘1’ - The Polarity of the PWM output driver is inverted. A drive setting of 00h will cause the output
to be set at 100% duty cycle and a drive setting of FFh will cause the output to be set at 0% duty
cycle.
7.19
PWM Driver Base Frequency Register
Table 7.26 PWM Driver Base Frequency Register
ADDR
R/W
REGISTER
B7
B6
B5
B4
B3
B2
B1
B0
DEFAULT
PWM Driver
Base
2Bh
R/W
-
-
-
-
-
-
PWM_BASE[1:0]
00h
Frequency
The PWM Driver Base Frequency Register controls base frequency of the PWM driver output.
Bits 1-0 - PWM_BASE[1:0] - Determines the base frequency of the PWM output driver.
Table 7.27 PWM_BASEx[1:0] it Decode
PWM_BASE[1:0]
1
0
BASE FREQUENCY
0
0
1
1
0
1
0
1
26.00kHz (default)
19.531kHz
4,882Hz
2,441Hz
Revision 1.2 (10-08-09)
SMSC EMC2113
DATA5S6HEET
SMSC [ SMSC CORPORATION ]
