EMC2104 Datasheet, PDF (58/101 Pages) SMSC Corporation – Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown

Dual RPM-Based PWM Fan Controller with Hardware Thermal Shutdown
Datasheet
„ ‘1’ - The VIN4 channel data is inverted. The data presented to the reading registers and compared
against the limits is determined as FFh - the measured input voltage.
APPLICATION NOTE: If the TRIP_SET / VIN4 pin is configured to be used to set the Critical / Thermal Shutdown
temperature associated with the External Diode 1 channel, then this bit cannot be set.
Bit 5 - VIN3_EN - Enables the voltage mode on the External Diode 3 channel.
„ ‘0’ (default) - The External Diode 3 channel operates as a diode channel.
„ ‘1’ - The External Diode 3 channel operates as a voltage input. The DP3 / DN4 / VREF_T3 pin
acts as a reference output voltage and the DN3 / DP4 /. VIN3 pin acts as a voltage input. This
overrides the APD bit in the Configuration 1 Register (20h).
Bit 4 - VIN3_INV - Determines whether the VIN3 channel data is inverted.
Bit 3 - VIN2_EN - Enables the voltage mode on the External Diode 2 channel.
Bit 2 - VIN2_INV - Determines whether the VIN2 channel data is inverted.
Bit 1 - VIN1_EN - Enables the voltage mode on the External Diode 1 channel.
Bit 0 - VIN1_INV - Determines whether the VIN1 channel data is inverted.
APPLICATION NOTE: If the TRIP_SET / VIN4 pin is configured to be used to set the Critical / Thermal Shutdown
temperature associated with the External Diode 1 channel, then neither Bit 1 nor Bit 0 can
be set.
6.12 Interrupt Status Register
ADDR
23h
Table 6.17 Interrupt Status Register
R/W REGISTER B7
Interrupt
R-C
Status
-
Register
B6
B5
B4
B3
B2
B1
B0 DEFAULT
TSD TCRIT GPIO FAN HIGH LOW FAULT
00h
The Interrupt Status Register reports the operating condition of the EMC2104. If any of the bits are set
to a logic ‘1’ (other than TSD and HWS) then the ALERT# pin will be asserted low if the corresponding
channel is enabled. Reading from the status register clears all status bits if the error conditions is
removed. If there are no set status bits, then the ALERT# pin will be released.
The bits that cause the ALERT# pin to be asserted can be masked based on the channel they are
associated with unless stated otherwise.
Bit 6 - TSD - This bit is set to ‘1’ if the internal Thermal Shutdown (TSD) circuit trips indicating that the
die temperature has exceeded its threshold. When this bit is set, it will not cause the ALERT# pin to
be asserted however will coincide with the SYS_SHDN# pin being asserted. This bit is cleared when
the register is read and the error condition has been removed.
Bit 5 - TCRIT - This bit is set to ‘1’ whenever the any bit in the Tcrit Status Register is set. This bit is
automatically cleared when the Tcrit Status Register is cleared.
Bit 4 - GPIO - This bit is set to ‘1’ if any of the bits in the GPIO Status Registers are set.
Bit 3 - FAN - This bit is set to ‘1’ if any bit in the Fan Status Register is set. This bit is automatically
cleared when the Fan Status Register is read and the bits are cleared.
Bit 2 - HIGH - This bit is set to ‘1’ if any bit in the High Status Register is set. This bit is automatically
cleared when the High Status Register is read and the bits are cleared.
Revision 1.74 (05-08-08)
58
DATASHEET
SMSC EMC2104