Hysteresis-Once Mode
The Hysteresis-Once operational mode can only be used in conjunction with the low-band or
high-band regions because the mid-band region must be crossed and the opposite region entered
to clear the hysteresis condition. In the Hysteresis-Once mode, the associated interrupt or trigger
is asserted only when the ADC conversion value meets its comparison criteria, the hysteresis
condition is clear, and the previous ADC conversion did not meet the comparison criteria. The result
is a single assertion on the interrupt or trigger.
15.3.7.3 Function Ranges
The two comparison values, COMP0 and COMP1, in the ADC Digital Comparator Range
(ADCDCCMPn) register effectively break the conversion area into three distinct regions. These
regions are referred to as the low-band (less than COMP0), mid-band (greater than COMP0 but less
than or equal to COMP1), and high-band (greater than or equal to COMP1) regions. COMP0 and COMP1
may be programmed to the same value, effectively creating two regions, but COMP1 must always
be greater than or equal to the value of COMP0. A COMP1 value that is less than COMP0 generates
unpredictable results.
Low-Band Operation
To operate in the low-band region, the CIC field or the CTC field in the ADCDCCTLn register must
be programmed to 0x0. This setting causes interrupts or triggers to be generated in the low-band
region as defined by the programmed operational mode. An example of the state of the
interrupt/trigger signal in the low-band region for each of the operational modes is shown in Figure
15-12 on page 1070. Note that a "0" in a column following the operational mode name (Always, Once,
Hysteresis Always, and Hysteresis Once) indicates that the interrupt or trigger signal is deasserted
and a "1" indicates that the signal is asserted.
Figure 15-12. Low-Band Operation (CIC=0x0 and/or CTC=0x0)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
0
1
0
1
0
1
0
0
0
1
0
0
0
1
0
1
1
1
0
1
0
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
Always –
Once –
Hysteresis Always –
Hysteresis Once –
COMP0
COMP1
June 18, 20141070
Texas Instruments-Production Data
Analog-to-Digital Converter (ADC)
To Next Page
Loading...
Need help?
General
