C8051F340/1/2/3/4/5/6/7
5.4.1. Window Detector In Single-Ended Mode
Figure 5.6 shows two example window comparisons for right-justified, single-ended data, with ADC0LTH:ADC0LTL = 0x0080 (128d) and ADC0GTH:ADC0GTL = 0x0040 (64d). In single-ended mode, 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 5.7 shows an exam- ple using left-justified data with equivalent ADC0GT and ADC0LT register settings.
| ADC0H:ADC0L |
Input Voltage |
|
(Px.x - GND) |
|
VREF x (1023/1024) | 0x03FF |
| 0x0081 |
VREF x (128/1024) | 0x0080 |
| 0x007F |
| 0x0041 |
VREF x (64/1024) | 0x0040 |
| 0x003F |
0 | 0x0000 |
|
| ADC0H:ADC0L |
| Input Voltage |
|
| (Px.x - GND) |
|
| VREF x (1023/1024) | 0x03FF |
AD0WINT |
|
|
not affected |
|
|
|
| 0x0081 |
ADC0LTH:ADC0LTL | VREF x (128/1024) | 0x0080 |
AD0WINT=1 |
| 0x007F |
| 0x0041 | |
|
| |
ADC0GTH:ADC0GTL | VREF x (64/1024) | 0x0040 |
|
| 0x003F |
AD0WINT |
|
|
not affected |
|
|
| 0 | 0x0000 |
AD0WINT=1
ADC0GTH:ADC0GTL
AD0WINT
not affected
ADC0LTH:ADC0LTL
AD0WINT=1
Figure 5.6. ADC Window Compare Example: Right-Justified Single-Ended Data
| ADC0H:ADC0L |
|
Input Voltage |
|
|
(Px.x - GND) |
|
|
VREF x (1023/1024) | 0xFFC0 |
|
|
| AD0WINT |
|
| not affected |
| 0x2040 |
|
VREF x (128/1024) | 0x2000 | ADC0LTH:ADC0LTL |
| 0x1FC0 | AD0WINT=1 |
| 0x1040 | |
|
| |
VREF x (64/1024) | 0x1000 | ADC0GTH:ADC0GTL |
| 0x0FC0 |
|
|
| AD0WINT |
|
| not affected |
0 | 0x0000 |
|
| ADC0H:ADC0L |
|
Input Voltage |
|
|
(Px.x - GND) |
|
|
VREF x (1023/1024) | 0xFFC0 |
|
|
| AD0WINT=1 |
| 0x2040 |
|
VREF x (128/1024) | 0x2000 | ADC0GTH:ADC0GTL |
| 0x1FC0 | AD0WINT |
|
| |
| 0x1040 | not affected |
|
| |
VREF x (64/1024) | 0x1000 | ADC0LTH:ADC0LTL |
| 0x0FC0 |
|
|
| AD0WINT=1 |
0 | 0x0000 |
|
Figure 5.7. ADC Window Compare Example: Left-Justified Single-Ended Data
54 | Rev. 0.5 |
