ADC built-in self-test

AN4371

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DocID025337 Rev 1

Figure 1. ADC block diagram

1.2

ADC self-test important note

In case of Injected conversions, test channel conversion is not performed. It is performed

only during Normal conversions. If during a test channel conversion, injection conversion

arrives, then the test channel is aborted (just as a normal functional channel) and injected

conversions are done. After injected conversions are completed, the test channel resumes

from the Step at which it was aborted.

For self testing, Mode bit should be programmed (at least one cycle) BEFORE setting

MCR.NSTART bit and should not be changed thereafter until conversion is ongoing.

1.3

ADC calibration data

To verify if the measured ADC BIST results are correct, the threshold registers are used. For

correct execution of self-test sequence it is necessary to compare if measured values are in

range of factory defined thresholds. This is done automatically by the hardware watchdog.

In case the ADC BIST results are out these boundaries a fault is triggered to the FCCU.

1.4

Reading from Test Flash

There are some factory settings stored during final test in the Test Flash (mostly calibration

information), which are needed by application software. The related data is:

a)

Temperature Sensor 1 Calibration Word 1...4

b)

Temperature Sensor 2 Calibration Word 1...4

c)

ADC 0 Calibration Word 1...8

d)

ADC 1 Calibration Word 1...8