STV3550 Datasheet, PDF (95/144 Pages) STMicroelectronics – LCD and Matrix Display TV Processor

STV3550
Conversions can be started by software or by a falling edge on the external trigger pin.
Figure 60: A/D Converter Trigger Source
Ext. Trigger Enable
ADC Trigger
Int. Trigger Enable
On-chip Event
Software Trigger
Start Group of Conversions
Continuous or Single Mode
End of Conversion Interrupt
An interrupt can be generated at the end of each conversion.
Analog Watchdog Interrupt
Moreover, another interrupt can be generated based on the upper or lower threshold limits of the
watchdog. See Section 7.6.4.
7.6.3.1 1-Channel mode
Only the selected analog input is converted. At the end of this conversion, the overflow status and
result are stored in the control registers of the selected channel.
7.6.3.2 Scan Mode
Up to 6 channels can be sequentially converted starting with Channel 0 and ending with Channel 7.
At the end of the conversion of each channel, the overflow status and result are stored in the control
register of the corresponding channel.
7.6.3.3 Single / Continuous Mode
Each main mode can run in either Single or Continuous mode.
In Single mode, the conversion sequence for the analog channel input is performed one single time.
In Continuous mode, the conversion sequence is performed continuously until reset by software.
7.6.4
Analog Watchdog
The Analog Watchdog is used to generate an interrupt based on two programmable threshold
levels.
For each channel, when the level of the analog input exceeds upper and lower threshold values, an
interrupt is generated.
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