C8051F120 Datasheet, PDF (103/356 Pages) Silicon Laboratories – Mixed Signal ISP Flash MCU Family

C8051F120/1/2/3/4/5/6/7
C8051F130/1/2/3
7.3.2. Window Detector In Differential Mode
Figure 7.11 shows two example window comparisons for differential mode, with ADC2LT = 0x10 (+16d)
and ADC2GT = 0xFF (-1d). Notice that in Differential mode, the codes vary from -VREF to VREF*(127/
128) and are represented as 8-bit 2’s complement signed integers. In the left example, an AD2WINT inter-
rupt will be generated if the ADC2 conversion word (ADC2L) is within the range defined by ADC2GT and
ADC2LT (if 0xFF (-1d) < ADC2 < 0x0F (16d)). In the right example, an AD2WINT interrupt will be gener-
ated if ADC2 is outside of the range defined by ADC2GT and ADC2LT (if ADC2 < 0xFF (-1d) or ADC2 >
0x10 (+16d)).
Input Voltage
(AIN2.x - AIN2.y)
REF x (127/128)
ADC2
0x7F (127d)
REF x (16/128)
REF x (-1/256)
0x11 (17d)
0x10 (16d)
0x0F (15d)
0x00 (0d)
0xFF (-1d)
0xFE (-2d)
AD2WINT
not affected
ADC2LT
AD2WINT=1
ADC2GT
Input Voltage
(AIN2.x - AIN2.y)
REF x (127/128)
ADC2
0x7F (127d)
REF x (16/128)
REF x (-1/256)
0x11 (17d)
0x10 (16d)
0x0F (15d)
0x00 (0d)
0xFF (-1d)
0xFE (-2d)
AD2WINT=1
ADC2GT
AD2WINT
not affected
ADC2LT
-REF
0x80 (-128d)
AD2WINT
not affected
-REF
0x80 (-128d)
AD2WINT=1
Figure 7.11. ADC2 Window Compare Examples, Differential Mode
Rev. 1.3
103