mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_ONSEMI/TARGET_NCS36510/ncs36510_trng_api.c@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
160:d5399cc887bb 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 150:02e0a0aed4ec 1 /**
<> 150:02e0a0aed4ec 2 ******************************************************************************
<> 150:02e0a0aed4ec 3 * @file trng_api.c
<> 150:02e0a0aed4ec 4 * @brief Implementation of TRNG functionality.
<> 150:02e0a0aed4ec 5 * @internal
<> 150:02e0a0aed4ec 6 * @author ON Semiconductor.
<> 150:02e0a0aed4ec 7 * $Rev: $
<> 150:02e0a0aed4ec 8 * $Date: $
<> 150:02e0a0aed4ec 9 ******************************************************************************
<> 150:02e0a0aed4ec 10 * Copyright 2016 Semiconductor Components Industries LLC (d/b/a “ON Semiconductor”).
<> 150:02e0a0aed4ec 11 * All rights reserved. This software and/or documentation is licensed by ON Semiconductor
<> 150:02e0a0aed4ec 12 * under limited terms and conditions. The terms and conditions pertaining to the software
<> 150:02e0a0aed4ec 13 * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf
<> 150:02e0a0aed4ec 14 * (“ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software”) and
<> 150:02e0a0aed4ec 15 * if applicable the software license agreement. Do not use this software and/or
<> 150:02e0a0aed4ec 16 * documentation unless you have carefully read and you agree to the limited terms and
<> 150:02e0a0aed4ec 17 * conditions. By using this software and/or documentation, you agree to the limited
<> 150:02e0a0aed4ec 18 * terms and conditions.
<> 150:02e0a0aed4ec 19 *
<> 150:02e0a0aed4ec 20 * THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED
<> 150:02e0a0aed4ec 21 * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF
<> 150:02e0a0aed4ec 22 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE.
<> 150:02e0a0aed4ec 23 * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL,
<> 150:02e0a0aed4ec 24 * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
<> 150:02e0a0aed4ec 25 * @endinternal
<> 150:02e0a0aed4ec 26 *
<> 150:02e0a0aed4ec 27 * @ingroup TRNG
<> 150:02e0a0aed4ec 28 *
<> 150:02e0a0aed4ec 29 */
<> 150:02e0a0aed4ec 30 #if DEVICE_TRNG
<> 150:02e0a0aed4ec 31
<> 150:02e0a0aed4ec 32 /*************************************************************************************************
<> 150:02e0a0aed4ec 33 * *
<> 150:02e0a0aed4ec 34 * Header files *
<> 150:02e0a0aed4ec 35 * *
<> 150:02e0a0aed4ec 36 *************************************************************************************************/
<> 150:02e0a0aed4ec 37 #include "trng_api.h"
<> 150:02e0a0aed4ec 38 #include "memory_map.h"
<> 150:02e0a0aed4ec 39 #include "ncs36510_trng.h"
<> 150:02e0a0aed4ec 40 #include "clock.h"
<> 160:d5399cc887bb 41 #include "mbed_wait_api.h"
<> 150:02e0a0aed4ec 42
<> 150:02e0a0aed4ec 43 /*************************************************************************************************
<> 150:02e0a0aed4ec 44 * *
<> 150:02e0a0aed4ec 45 * Functions *
<> 150:02e0a0aed4ec 46 * *
<> 150:02e0a0aed4ec 47 *************************************************************************************************/
<> 150:02e0a0aed4ec 48
<> 150:02e0a0aed4ec 49
<> 150:02e0a0aed4ec 50 void trng_init(trng_t *obj)
<> 150:02e0a0aed4ec 51 {
<> 150:02e0a0aed4ec 52 /* Enable TRNG */
<> 150:02e0a0aed4ec 53 CLOCK_ENABLE(CLOCK_RAND);
<> 150:02e0a0aed4ec 54
<> 150:02e0a0aed4ec 55 /* Initialize TRNG */
<> 150:02e0a0aed4ec 56 RANDREG->CONTROL.WORD = False;
<> 150:02e0a0aed4ec 57
<> 150:02e0a0aed4ec 58 return;
<> 150:02e0a0aed4ec 59 }
<> 150:02e0a0aed4ec 60 void trng_free(trng_t *obj)
<> 150:02e0a0aed4ec 61 {
<> 150:02e0a0aed4ec 62 /* Stop TRNG */
<> 150:02e0a0aed4ec 63 RANDREG->CONTROL.WORD = False;
<> 150:02e0a0aed4ec 64
<> 150:02e0a0aed4ec 65 /* Disable TRNG */
<> 150:02e0a0aed4ec 66 CLOCK_DISABLE(CLOCK_RAND);
<> 150:02e0a0aed4ec 67
<> 150:02e0a0aed4ec 68 return;
<> 150:02e0a0aed4ec 69 }
<> 150:02e0a0aed4ec 70
<> 150:02e0a0aed4ec 71 int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length)
<> 150:02e0a0aed4ec 72 {
<> 150:02e0a0aed4ec 73 uint32_t MSLRandom = 0, Index, TempLen, *TempPtr = (uint32_t*)output;
<> 150:02e0a0aed4ec 74
<> 150:02e0a0aed4ec 75 RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_ENABLE; /* ENable MSL TRNG */
<> 150:02e0a0aed4ec 76 RANDREG->CONTROL.BITS.MEATSTABLE_SPEED = TRNG_FAST_MODE; /* Meta-stable Latch TRNG Speed Control */
<> 150:02e0a0aed4ec 77 RANDREG->CONTROL.BITS.MODE = TRNG_ON_READ_EVENT; /* TRNG is only updated on a read event of the TRNG register */
<> 150:02e0a0aed4ec 78
<> 150:02e0a0aed4ec 79 wait_us(1); /* Wait till MSL generates random number after enable for the first time */
<> 150:02e0a0aed4ec 80
<> 150:02e0a0aed4ec 81 TempLen = length / 4;
<> 150:02e0a0aed4ec 82
<> 150:02e0a0aed4ec 83 for(Index = 0; Index < TempLen; Index++)
<> 150:02e0a0aed4ec 84 {
<> 150:02e0a0aed4ec 85 MSLRandom = RANDREG->METASTABLE_LATCH_VAL;
<> 150:02e0a0aed4ec 86 *TempPtr++ = MSLRandom ;
<> 150:02e0a0aed4ec 87 }
<> 150:02e0a0aed4ec 88
<> 150:02e0a0aed4ec 89 TempLen = length % 4;
<> 150:02e0a0aed4ec 90 Index *= 4;
<> 150:02e0a0aed4ec 91
<> 150:02e0a0aed4ec 92 if(TempLen-- > 0)
<> 150:02e0a0aed4ec 93 {
<> 150:02e0a0aed4ec 94 MSLRandom = RANDREG->METASTABLE_LATCH_VAL;
<> 150:02e0a0aed4ec 95 *(output + Index++) = (MSLRandom >> 0) & 0xFF;
<> 150:02e0a0aed4ec 96 if(TempLen-- > 0)
<> 150:02e0a0aed4ec 97 {
<> 150:02e0a0aed4ec 98 *(output + Index++) = (MSLRandom >> 8) & 0xFF;
<> 150:02e0a0aed4ec 99 if(TempLen-- > 0)
<> 150:02e0a0aed4ec 100 {
<> 150:02e0a0aed4ec 101 *(output + Index++) = (MSLRandom >> 16) & 0xFF;
<> 150:02e0a0aed4ec 102 }
<> 150:02e0a0aed4ec 103 }
<> 150:02e0a0aed4ec 104 }
<> 150:02e0a0aed4ec 105
<> 150:02e0a0aed4ec 106 RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_DISABLE; /* Disable MSL */
<> 150:02e0a0aed4ec 107
<> 150:02e0a0aed4ec 108 *output_length = Index;
<> 150:02e0a0aed4ec 109
<> 150:02e0a0aed4ec 110 return 0; /* Success */
<> 150:02e0a0aed4ec 111 }
<> 150:02e0a0aed4ec 112
<> 150:02e0a0aed4ec 113 #endif /* DEVICE_TRNG */