Notes

The true random number generator continuously generates new bits. Each new bit is shifted into the RNGSEED register from the right.

Old bit ← RNGSEED2 ← RNGSEED1 ← New bit.

Example

ao_leds_t ld;
ao_leds_t le;

uint32_t v;

ao_rngt_enable();

while (1)
{
    // Wait until 3 bits have been generated.
    while (ao_rngt_bits() < 3);

    // Read the random number.
    v = ao_rngt_value_lo();
    v = v & 0b111;

    // LEDs.

    le = AO_LEDS_NONE;
    ld = AO_LEDS_NONE;

    if (v & (1 << 0)) { le |= AO_LEDS_0; } else { ld |= AO_LEDS_0; }
    if (v & (1 << 1)) { le |= AO_LEDS_1; } else { ld |= AO_LEDS_1; }
    if (v & (1 << 2)) { le |= AO_LEDS_2; } else { ld |= AO_LEDS_2; }

    ao_leds_enable(le);
    ao_leds_disable(ld);

    // Spin.
    ao_spin(AO_MILLISECONDS(100));
}

Include

stdint.h

xc.h

Functions

`ao_rngt_enable`

`ao_rngt_disable`

#define ao_rngt_enable()  { RNGCONbits.TRNGEN = 1; }
#define ao_rngt_disable() { RNGCONbits.TRNGEN = 0; }

Enables or disables the true random number generator.

`ao_rngt_bits`

#define ao_rngt_bits() (RNGCNT)

Gets the number of bits that have been generate since the last read.

`ao_rngt_value`

#define ao_rngt_value()           \
(                                 \
    ((uint64_t) RNGSEED2 << 32) | \
     (uint64_t) RNGSEED1          \
)

Gets the generated value.

`ao_rngt_value_hi`

`ao_rngt_value_lo`

#define ao_rngt_value_hi() (RNGSEED2)
#define ao_rngt_value_lo() (RNGSEED1)

Gets the most or least significant 32 bits, respectively, of the generated value.

October 13, 2022

This page is under construction.

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