C8051F80X_14 Datasheet, PDF (55/251 Pages) Silicon Laboratories – Mixed Signal ISP Flash MCU Family

C8051F80x-83x
8.4.1. Window Detector Example
Figure 8.4 shows two example window comparisons for right-justified data, with
ADC0LTH:ADC0LTL = 0x0080 (128d) and ADC0GTH:ADC0GTL = 0x0040 (64d). The input voltage can
range from 0 to VREF x (1023/1024) with respect to GND, and is represented by a 10-bit unsigned integer
value. In the left example, an AD0WINT interrupt will be generated if the ADC0 conversion word
(ADC0H:ADC0L) is within the range defined by ADC0GTH:ADC0GTL and ADC0LTH:ADC0LTL
(if 0x0040 < ADC0H:ADC0L < 0x0080). In the right example, and AD0WINT interrupt will be generated if
the ADC0 conversion word is outside of the range defined by the ADC0GT and ADC0LT registers
(if ADC0H:ADC0L < 0x0040 or ADC0H:ADC0L > 0x0080). Figure 8.5 shows an example using left-justi-
fied data with the same comparison values.
Input Voltage
(AIN - GND)
VREF x (1023/
1024)
ADC0H:ADC0L
0x03FF
VREF x (128/1024)
VREF x (64/1024)
0x0081
0x0080
0x007F
0x0041
0x0040
0x003F
AD0WINT
not affected
Input Voltage
(AIN - GND)
VREF x (1023/
1024)
ADC0H:ADC0L
0x03FF
ADC0LTH:ADC0LTL
AD0WINT=1
ADC0GTH:ADC0GTL
VREF x (128/1024)
VREF x (64/1024)
0x0081
0x0080
0x007F
0x0041
0x0040
0x003F
AD0WINT=1
ADC0GTH:ADC0GTL
AD0WINT
not affected
ADC0LTH:ADC0LTL
0
0x0000
AD0WINT
not affected
0
0x0000
AD0WINT=1
Figure 8.4. ADC Window Compare Example: Right-Justified Data
Input Voltage
(AIN - GND)
VREF x (1023/
1024)
ADC0H:ADC0L
0xFFC0
VREF x (128/1024)
VREF x (64/1024)
0x2040
0x2000
0x1FC0
0x1040
0x1000
0x0FC0
AD0WINT
not affected
Input Voltage
(AIN - GND)
VREF x (1023/
1024)
ADC0H:ADC0L
0xFFC0
ADC0LTH:ADC0LTL
AD0WINT=1
ADC0GTH:ADC0GTL
VREF x (128/1024)
VREF x (64/1024)
0x2040
0x2000
0x1FC0
0x1040
0x1000
0x0FC0
AD0WINT=1
ADC0GTH:ADC0GTL
AD0WINT
not affected
ADC0LTH:ADC0LTL
0
0x0000
AD0WINT
not affected
0
0x0000
AD0WINT=1
Figure 8.5. ADC Window Compare Example: Left-Justified Data
Rev. 1.0
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