FreeRTOS/Demo/CORTEX_A5_SAMA5D4x_EK_IAR/AtmelFiles/libchip_sama5d4x/source/trng.c

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/** \addtogroup rtng_module Working with RTNG
 * \ingroup peripherals_module
 * The TRNG driver provides the interface to configure and use the TRNG peripheral.
 * \n
 *
 * 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 :\n
 * \ref trng.c\n
 * \ref trng.h\n
 */
/*@{*/
/*@}*/

/**
 * \file
 *
 * Implementation of True Random Number Generator (TRNG)
 *
 */


/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "chip.h"

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Enables the TRNG to provide Random Values.
 * \param key  This key is to be written when the ENABLE bit is set.
 */
void TRNG_Enable(uint32_t key)
{
    TRNG->TRNG_CR = TRNG_CR_ENABLE | TRNG_CR_KEY(key);
}

/**
 * \brief Disables the TRNG to provide Random Values.
 * \param key  This key is to be written when the DISABLE bit is set.
 */
void TRNG_Disable(uint32_t key)
{
    TRNG->TRNG_CR = TRNG_CR_KEY(key);
}

/**
 * \brief Data Ready Interrupt enable.
 */
void TRNG_EnableIt(void)
{
    TRNG->TRNG_IER = TRNG_IER_DATRDY;
}

/**
 * \brief Data Ready Interrupt Disable.
 */
void TRNG_DisableIt(void)
{
    TRNG->TRNG_IDR = TRNG_IDR_DATRDY;
}

/**
 * \brief Get the current status register of the given TRNG peripheral.
 * \return  TRNG status register.
 */
uint32_t TRNG_GetStatus(void)
{
    return TRNG->TRNG_ISR;
}

/**
 * \brief Get the  32-bit Output Data from TRNG peripheral.
 * \return  TRNG output data.
 */
uint32_t TRNG_GetRandData(void)
{
    return TRNG->TRNG_ODATA;
}