Datasheet

MCP9600
DS20005426C-page 34  2015-2017 Microchip Technology Inc.
5.3.3 ALERT CONFIGURATION
REGISTERS
This device integrates four individually controlled
temperature alert outputs. Each output is configured for
the corresponding alert output using the Alert Output
Configuration registers.
The Configuration registers are used to enable each
output, select the Alert Function mode as Comparator
or Interrupt mode, active-high or active-low output,
detect rising or falling temperatures and detect T
H
or
T
C
Temperature registers.
The Comparator mode is useful for thermostat-type
applications, such as on/off switches for fan controllers,
buzzer or LED indicators. The alert output asserts and
deasserts when the temperature exceeds the
user-specified limit, and the user-specified hysteresis
limit. The Interrupt mode is useful for interrupt driven
microcontroller-based systems. The alert outputs are
asserted each time the temperature exceeds the
user-specified alert limit and hysteresis limits.
The microcontroller will have Acknowledged the
interrupt signal from the corresponding alert output by
clearing the interrupt using bit 7 of the corresponding
Configuration register.
The Rise/Fall bit (bit 3) and the Monitor T
H
/T
C
bit (bit 4)
can be used to detect and maintain the thermocouple
temperature or the cold-junction temperature to the
desired temperature window.
TABLE 5-6: ALERT CONFIG. REGISTERS
Register Register Pointer
Alert 1 Configuration 0000 1000
Alert 2 Configuration 0000 1001
Alert 3 Configuration 0000 1010
Alert 4 Configuration 0000 1011
REGISTER 5-11: ALERT 1, 2, 3 AND 4 CONFIGURATION REGISTER
R/W-0 U-0 U-0 R/W-0 R/W-0 R-0 R-0 R-0
Interrupt Clear
— — Monitor T
H
/T
C
Rise/Fall Active-High/Low Comp/Int. Alert Enable
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7 Interrupt Clear: Interrupt Clear bit
1 = Clears Interrupt flag (forced ‘0’ by device)
0 = Normal state or cleared state
bit 6-5 Unimplemented: Read as ‘0’
bit 4 Monitor T
H
or T
C
: Temperature Maintain/Detect bit
1 = Alert monitor for T
C
cold-junction sensor
0 = Alert monitor for T
H
thermocouple temperature
bit 3 Rise/Fall: Alert Temperature Direction bit
1 = Alert limit for rising or heating temperatures
0 = Alert limit for falling or cooling temperatures
bit 2 Active-High/Low: Alert State bit
1 = Active-high
0 = Active-low
bit 1 Comp./Int.: Alert Mode bit
1 = Interrupt mode: Interrupt clears bit (bit 7) – must be set to deassert the alert output
0 = Comparator mode
bit 0 Alert Enable: Alert Output Enable bit
1 = Alert output is enabled
0 = Alert output is disabled