NRF52811-QCAA-R datasheet(264/444 Pages) NORDIC

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Peripherals

Sample and convert RAM

Result 0

Result 1

Result 2

Result 3

0x20000000

0x20000002

0x20000010

0x20000012

0x20000020

0x20000022

Data RAM

Figure 107: ADC

If the RESULT.PTR is not pointing to the Data RAM region, an EasyDMA transfer may result in a HardFault

or RAM corruption. See Memory on page 16 for more information about the different memory regions.

The EasyDMA will have finished accessing the RAM when the END or STOPPED event has been generated.

The RESULT.AMOUNT register can be read following an END event or a STOPPED event to see how many

results have been transferred to the Result buffer in RAM since the START task was triggered.

In scan mode, SAMPLE tasks can be triggered once the START task is triggered. The END event is generated

when the number of samples transferred to memory reaches the value specified by RESULT.MAXCNT.

After an END event, the START task needs to be triggered again before new samples can be taken. Also

make sure that the size of the Result buffer is large enough to have space for minimum one result from

each of the enabled channels, by specifying RESULT.MAXCNT >= number of channels enabled. For more

information about the scan mode, see Scan mode on page 262.

6.17.7 Resistor ladder

The ADC has an internal resistor string for positive and negative input.

See Resistor ladder for positive input (negative input is equivalent, using RESN instead of RESP) on page

265. The resistors are controlled in the CH[n].CONFIG.RESP and CH[n].CONFIG.RESN registers.

4454_140 v1.0

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