Mouse code for the MacroRat
mbed-dev/targets/TARGET_ONSEMI/TARGET_NCS36510/ncs36510_trng_api.c
- Committer:
- sahilmgandhi
- Date:
- 2017-05-14
- Revision:
- 18:6a4db94011d3
File content as of revision 18:6a4db94011d3:
/** ****************************************************************************** * @file trng_api.c * @brief Implementation of TRNG functionality. * @internal * @author ON Semiconductor. * $Rev: $ * $Date: $ ****************************************************************************** * Copyright 2016 Semiconductor Components Industries LLC (d/b/a ON Semiconductor). * All rights reserved. This software and/or documentation is licensed by ON Semiconductor * under limited terms and conditions. The terms and conditions pertaining to the software * and/or documentation are available at http://www.onsemi.com/site/pdf/ONSEMI_T&C.pdf * (ON Semiconductor Standard Terms and Conditions of Sale, Section 8 Software) and * if applicable the software license agreement. Do not use this software and/or * documentation unless you have carefully read and you agree to the limited terms and * conditions. By using this software and/or documentation, you agree to the limited * terms and conditions. * * THIS SOFTWARE IS PROVIDED "AS IS". NO WARRANTIES, WHETHER EXPRESS, IMPLIED * OR STATUTORY, INCLUDING, BUT NOT LIMITED TO, IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. * ON SEMICONDUCTOR SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, * INCIDENTAL, OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER. * @endinternal * * @ingroup TRNG * */ #if DEVICE_TRNG /************************************************************************************************* * * * Header files * * * *************************************************************************************************/ #include "trng_api.h" #include "memory_map.h" #include "ncs36510_trng.h" #include "clock.h" #include "mbed_wait_api.h" /************************************************************************************************* * * * Functions * * * *************************************************************************************************/ void trng_init(trng_t *obj) { /* Enable TRNG */ CLOCK_ENABLE(CLOCK_RAND); /* Initialize TRNG */ RANDREG->CONTROL.WORD = False; return; } void trng_free(trng_t *obj) { /* Stop TRNG */ RANDREG->CONTROL.WORD = False; /* Disable TRNG */ CLOCK_DISABLE(CLOCK_RAND); return; } int trng_get_bytes(trng_t *obj, uint8_t *output, size_t length, size_t *output_length) { uint32_t MSLRandom = 0, Index, TempLen, *TempPtr = (uint32_t*)output; RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_ENABLE; /* ENable MSL TRNG */ RANDREG->CONTROL.BITS.MEATSTABLE_SPEED = TRNG_FAST_MODE; /* Meta-stable Latch TRNG Speed Control */ RANDREG->CONTROL.BITS.MODE = TRNG_ON_READ_EVENT; /* TRNG is only updated on a read event of the TRNG register */ wait_us(1); /* Wait till MSL generates random number after enable for the first time */ TempLen = length / 4; for(Index = 0; Index < TempLen; Index++) { MSLRandom = RANDREG->METASTABLE_LATCH_VAL; *TempPtr++ = MSLRandom ; } TempLen = length % 4; Index *= 4; if(TempLen-- > 0) { MSLRandom = RANDREG->METASTABLE_LATCH_VAL; *(output + Index++) = (MSLRandom >> 0) & 0xFF; if(TempLen-- > 0) { *(output + Index++) = (MSLRandom >> 8) & 0xFF; if(TempLen-- > 0) { *(output + Index++) = (MSLRandom >> 16) & 0xFF; } } } RANDREG->CONTROL.BITS.METASTABLE_LATCH_EN = TRNG_DISABLE; /* Disable MSL */ *output_length = Index; return 0; /* Success */ } #endif /* DEVICE_TRNG */