EMC2106 Datasheet, PDF (85/106 Pages) SMSC Corporation – Dual RPM-Based Linear Fan Controller with Hardware Thermal Shutdown

Dual RPM-Based Linear Fan Controller with Hardware Thermal Shutdown
Datasheet
Table 6.56 GPIO5_CFG[1:0] Decode
GPIO5_CFG[1:0]
1
0
0
1
1
0
0
1
0
1
OVERT3# / GPIO5 / PWM4 PIN FUNCTION
OVERT3# - the pin will act as a dedicated alert for the External
Diode 2 channel (default)
GPIO - the pin will act as a GPIO
GPIO - the pin will act as a GPIO
PWM - the pin will act as a PWM output controlled by the PWM4
Setting Register
Bits 4 - 3 - GPIO4_CFG[1:0] - Determines the pin functions for the OVERT2# / GPIO4 / PWM3 pin as
shown in Table 6.57. When not configured as an output, all PWM3 controls will be ignored though can
be updated normally.
Table 6.57 GPIO4_CFG[1:0] Decode
GPIO4_CFG[1:0]
1
0
0
1
1
0
0
1
0
1
OVERT2# / GPIO4 / PWM3 PIN FUNCTION
OVERT2# - the pin will act as a dedicated alert for the External
Diode 2 channel (default)
GPIO - the pin will act as a GPIO
GPIO - the pin will act as a GPIO
PWM - the pin will act as a PWM output controlled by the PWM3
Setting Register
Bit 2 - GPIO3_CFG - Determines the pin function for the PWM2 / GPIO3 pin as well as the DAC2 pin.
„ ‘0’ (default) - The PWM2/ GPIO3 pin functions as a PWM output for the 2nd the RPM based Fan
Speed Control Algorithm (FSC). The Linear DAC Fan Driver is disabled and the DAC2 pin will be
in a high impedance state.
„ ‘1’ - The PWM2 / GPIO3 pin functions as a GPIO. The Linear DAC Fan Driver is enabled and
driven by the 2nd RPM based Fan Speed Control Algorithm (FSC). All PWM2 controls will be
ignored though are still writable via the SMBus.
Bit 1 - GPIO2_CFG - Determines the pin functions for the TACH2 / GPIO2 pin.
„ ‘0’ (default) - The TACH2 / GPIO2 pin functions as a tachometer input for the 2nd the RPM based
Fan Speed Control Algorithm (FSC).
„ ‘1’ - The TACH2 / GPIO2 pin functions as a GPIO. When set, the EN_ALGO2 bit will automatically
be set to ‘0’ and cannot be set.
Bit 0 - GPIO1_CFG - Determines the pin function for the CLK_IN / GPIO1 pin.
„ ‘0’ - The CLK_IN / GPIO1 pin functions as a clock input for the RPM based Fan Speed Control
Algorithm (FSC).
„ ‘1’ (default) - The CLK_IN / GPIO1 pin functions as a GPIO.
SMSC EMC2106
85
DATASHEET
Revision 1.72 (11-01-07)