9.4.6.16 Buffer Structure

The DMA read channel is triggered each time a new data is stored in ADC_LCDR. The same data structure is repeatedly stored in ADC_LCDR each time a trigger event occurs. Depending on user mode of operation (ADC_MR, ADC_CHSR, ADC_SEQR1, ADC_TSMR) the structure differs. Each data read to DMA buffer, carried on a half-word (16-bit), consists of last converted data right-aligned and when the ADC_EMR.TAG is set, the four most significant bits are carrying the channel number thus allowing an easier postprocessing in the DMA buffer or better checking the DMA buffer integrity.

Figure 9-45.  Buffer Structure

As soon as touchscreen conversions are required, the pen detection function can help the postprocessing of the buffer. See Pen Detection Status.