3.4 Interrupt Status Register, RNG_ISR

The RNG_ISR register returns the status of the interrupts.

If the corresponding RNG_IMR bit is unmasked, then an interrupt is generated.

The following table lists the RNG_ISR bit assignments.

Table 3-4 RNG_ISR

Bits Name Description
[31:4] - Reserved.
[3] VN_ERR

When set to 1 it indicates a Von Neumann error.

A Von Neumann error occurs if 32 consecutive collected bits are identical, that is, 32 zeros or 32 ones.


When set to 1, it indicates a Continuous Random Number Generation Testing (CRNGT) error in the TRNG test failed.

Failure occurs when two consecutive blocks of 16 collected bits are equal.


When set to 1, it indicates that the Autocorrelation test failed four times in a row.

When set, the TRNG stops functioning until the next reset.

[0] EHR_VALID Set to 1 when 192 bits have been collected in the TRNG, and the EHR_DATA[0, 1, 2,…5] registers are ready to be read.
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