C8051F336_08 Datasheet, PDF (47/227 Pages) Silicon Laboratories – Mixed-Signal Byte-Programmable EPROM MCU

C8051F336/7/8/9
7.3.2. Window Detector In Differential Mode
Figure 7.6 shows two example window comparisons for right-justified, differential data, with
ADC0LTH:ADC0LTL = 0x0040 (+64d) and ADC0GTH:ADC0GTH = 0xFFFF (–1d). In differential mode, the
measurable voltage between the input pins is between –VREF and VREF x (511/512). Output codes are
represented as 10-bit 2s complement signed integers. 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 0xFFFF (–1d) < ADC0H:ADC0L < 0x0040 (64d)). In the
right example, an 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 < 0xFFFF (–1d) or
ADC0H:ADC0L > 0x0040 (+64d)). Figure 7.7 shows an example using left-justified data with the same
comparison values.
ADC0H:ADC0L
Input Voltage
(Px.x - Px.x)
VREF x (511/512)
0x01FF
VREF x (64/512)
VREF x (-1/512)
0x0041
0x0040
0x003F
0x0000
0xFFFF
0xFFFE
AD0WINT
not affected
ADC0LTH:ADC0LTL
AD0WINT=1
ADC0GTH:ADC0GTL
ADC0H:ADC0L
Input Voltage
(Px.x - Px.x)
VREF x (511/512)
0x01FF
VREF x (64/512)
VREF x (-1/512)
0x0041
0x0040
0x003F
0x0000
0xFFFF
0xFFFE
AD0WINT=1
ADC0GTH:ADC0GTL
AD0WINT
not affected
ADC0LTH:ADC0LTL
-VREF
0x0200
AD0WINT
not affected
-VREF
0x0200
AD0WINT=1
Figure 7.6. ADC Window Compare Example: Right-Justified Differential Data
ADC0H:ADC0L
Input Voltage
(Px.x - Px.x)
VREF x (511/512)
0x7FC0
VREF x (64/512)
VREF x (-1/512)
0x1040
0x1000
0x0FC0
0x0000
0xFFC0
0xFF80
AD0WINT
not affected
ADC0LTH:ADC0LTL
AD0WINT=1
ADC0GTH:ADC0GTL
ADC0H:ADC0L
Input Voltage
(Px.x - Px.y)
VREF x (511/512)
0x7FC0
VREF x (64/512)
VREF x (-1/512)
0x1040
0x1000
0x0FC0
0x0000
0xFFC0
0xFF80
AD0WINT=1
ADC0GTH:ADC0GTL
AD0WINT
not affected
ADC0LTH:ADC0LTL
-VREF
0x8000
AD0WINT
not affected
-VREF
0x8000
AD0WINT=1
Figure 7.7. ADC Window Compare Example: Left-Justified Differential Data
Rev.1.0
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