1 | /* ---------------------------------------------------------------------------- */ |
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2 | /* Atmel Microcontroller Software Support */ |
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3 | /* SAM Software Package License */ |
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4 | /* ---------------------------------------------------------------------------- */ |
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5 | /* Copyright (c) 2015, Atmel Corporation */ |
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6 | /* */ |
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7 | /* All rights reserved. */ |
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8 | /* */ |
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9 | /* Redistribution and use in source and binary forms, with or without */ |
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10 | /* modification, are permitted provided that the following condition is met: */ |
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11 | /* */ |
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12 | /* - Redistributions of source code must retain the above copyright notice, */ |
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13 | /* this list of conditions and the disclaimer below. */ |
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14 | /* */ |
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15 | /* Atmel's name may not be used to endorse or promote products derived from */ |
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16 | /* this software without specific prior written permission. */ |
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17 | /* */ |
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18 | /* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR */ |
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19 | /* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF */ |
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20 | /* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE */ |
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21 | /* DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, */ |
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22 | /* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT */ |
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23 | /* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, */ |
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24 | /* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF */ |
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25 | /* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING */ |
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26 | /* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, */ |
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27 | /* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ |
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28 | /* ---------------------------------------------------------------------------- */ |
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29 | |
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30 | /** \addtogroup rtng_module Working with RTNG |
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31 | * \ingroup peripherals_module |
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32 | * The TRNG driver provides the interface to configure and use the TRNG |
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33 | * peripheral.\n |
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34 | * |
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35 | * The True Random Number Generator (TRNG) passes the American NIST Special |
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36 | * Publication 800-22 and Diehard Random Tests Suites. As soon as the TRNG is |
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37 | * enabled (TRNG_Enable()), the generator provides one 32-bit value every 84 |
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38 | * clock cycles. Interrupt trng_int can be enabled through TRNG_EnableIt() |
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39 | * (respectively disabled in TRNG_IDR). |
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40 | * This interrupt is set when a new random value is available and is cleared |
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41 | * when the status register is read (TRNG_SR register). The flag DATRDY of |
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42 | * the status register (TRNG_ISR) is set when the random data is ready to be |
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43 | * read out on the 32-bit output data through TRNG_GetRandData(). |
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44 | * |
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45 | * For more accurate information, please look at the SHA section of the |
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46 | * Datasheet. |
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47 | * |
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48 | * Related files :\n |
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49 | * \ref trng.c\n |
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50 | * \ref trng.h\n |
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51 | */ |
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52 | /*@{*/ |
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53 | /*@}*/ |
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54 | |
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55 | /** |
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56 | * \file |
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57 | * |
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58 | * Implementation of True Random Number Generator (TRNG) |
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59 | * |
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60 | */ |
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61 | |
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62 | /*---------------------------------------------------------------------------- |
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63 | * Headers |
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64 | *----------------------------------------------------------------------------*/ |
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65 | |
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66 | #include "chip.h" |
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67 | |
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68 | /*---------------------------------------------------------------------------- |
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69 | * Exported functions |
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70 | *----------------------------------------------------------------------------*/ |
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71 | |
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72 | /** |
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73 | * \brief Enables the TRNG to provide Random Values. |
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74 | * \param key This key is to be written when the ENABLE bit is set. |
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75 | */ |
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76 | void TRNG_Enable(void) |
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77 | { |
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78 | TRNG->TRNG_CR = TRNG_CR_ENABLE | TRNG_CR_KEY_PASSWD; |
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79 | } |
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80 | |
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81 | /** |
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82 | * \brief Disables the TRNG to provide Random Values. |
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83 | * \param key This key is to be written when the DISABLE bit is set. |
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84 | */ |
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85 | void TRNG_Disable(void) |
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86 | { |
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87 | TRNG->TRNG_CR = TRNG_CR_KEY_PASSWD; |
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88 | } |
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89 | |
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90 | /** |
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91 | * \brief Data Ready Interrupt enable. |
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92 | */ |
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93 | void TRNG_EnableIt(void) |
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94 | { |
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95 | TRNG->TRNG_IER = TRNG_IER_DATRDY; |
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96 | } |
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97 | |
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98 | /** |
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99 | * \brief Data Ready Interrupt Disable. |
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100 | */ |
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101 | void TRNG_DisableIt(void) |
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102 | { |
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103 | TRNG->TRNG_IDR = TRNG_IDR_DATRDY; |
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104 | } |
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105 | |
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106 | /** |
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107 | * \brief Get the current status register of the given TRNG peripheral. |
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108 | * \return TRNG status register. |
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109 | */ |
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110 | uint32_t TRNG_GetStatus(void) |
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111 | { |
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112 | return TRNG->TRNG_ISR; |
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113 | } |
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114 | |
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115 | /** |
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116 | * \brief Get the 32-bit Output Data from TRNG peripheral. |
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117 | * \return TRNG output data. |
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118 | */ |
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119 | uint32_t TRNG_GetRandData(void) |
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120 | { |
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121 | return TRNG->TRNG_ODATA; |
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122 | } |
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