AN3018

Self tests for SPC564Ax analog peripherals

Doc ID 16081 Rev 2

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Result: obtained by checking the ADC conversion result of the selected differential input.

Resource availability: selecting pull up and pull down may affect the precision of regular

conversions performed during the time they are activated.

5.4

Supply monitor self tests

SPC564Ax devices have supply monitors for 5 V, 3.3 V (internally generated) and 1.2 V.

The 1.2 V monitor is testable.

5.4.1

1.2 V monitor check

Principle: reset or interrupt can be selected for a 1.2 V loss. By enabling interrupt and

changing the trimmed value and its threshold, it is possible to test the 1.2 V monitor.

Result: a 1.2 V error is reported when the threshold of the monitor is set lower than 1.2 V.

Resource availability: 1.2 V monitor is not available during this test.

5.4.2

Monitor check using eQADC

Principle: the analog multiplexer allows for convertion of any of the supplies (5 V, 3.3 V,

1.2 V). This also includes the reference voltage for 1.2 V.

Result: obtained by checking the ADC conversion result.

Resource availability: all LVIs should be disabled during this test.

Note that the 1.2 V is derived from a reference independent of the ADC VREF, so that the

1.2 V check with ADC allows checking of the ADC reference voltage.

5.5

Summary for analog peripherals

The table below summarizes the self tests for analog peripherals.

Table 2.

Self tests for analog peripherals

Module

Self test

Comments

PLL

Use CQM

-

ADC

ADC reference check, ADC mux and analog input check

-

1.2 V monitor Change the 1.2 V threshold.

-

PMC

Use ADC to measure the supplies (5

self tests for analog

-

Oscillator

Use CQM

-