The TRNG driver provides the interface to configure and use the TRNG peripheral.
The True Random Number Generator (TRNG) passes the American NIST Special Publication 800-22 and Diehard Random Tests Suites. As soon as the TRNG is enabled (TRNG_Enable()), the generator provides one 32-bit value every 84 clock cycles. Interrupt trng_int can be enabled through TRNG_EnableIt() (respectively disabled in TRNG_IDR). This interrupt is set when a new random value is available and is cleared when the status register is read (TRNG_SR register). The flag DATRDY of the status register (TRNG_ISR) is set when the random data is ready to be read out on the 32-bit output data through TRNG_GetRandData().

For more accurate information, please look at the SHA section of the Datasheet.

Related files :
trng.c
trng.h