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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_trng.c] - Blame information for rev 23

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// #################################################################################################
// # << NEORV32: neorv32_trng.c - True Random Number Generator (TRNG) HW Driver >>                 #
// # ********************************************************************************************* #
// # BSD 3-Clause License                                                                          #
// #                                                                                               #
// # Copyright (c) 2020, Stephan Nolting. All rights reserved.                                     #
// #                                                                                               #
// # Redistribution and use in source and binary forms, with or without modification, are          #
// # permitted provided that the following conditions are met:                                     #
// #                                                                                               #
// # 1. Redistributions of source code must retain the above copyright notice, this list of        #
// #    conditions and the following disclaimer.                                                   #
// #                                                                                               #
// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of     #
// #    conditions and the following disclaimer in the documentation and/or other materials        #
// #    provided with the distribution.                                                            #
// #                                                                                               #
// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to  #
// #    endorse or promote products derived from this software without specific prior written      #
// #    permission.                                                                                #
// #                                                                                               #
// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS   #
// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF               #
// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE    #
// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,     #
// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #
// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED    #
// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING     #
// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED  #
// # OF THE POSSIBILITY OF SUCH DAMAGE.                                                            #
// # ********************************************************************************************* #
// # The NEORV32 Processor - https://github.com/stnolting/neorv32              (c) Stephan Nolting #
// #################################################################################################
 
 
/**********************************************************************//**
 * @file neorv32_trng.c
 * @author Stephan Nolting
 * @brief True Random Number Generator (TRNG) HW driver source file.
 *
 * @note These functions should only be used if the TRNG unit was synthesized (IO_TRNG_USE = true).
 **************************************************************************/
 
#include "neorv32.h"
#include "neorv32_trng.h"
 
 
/**********************************************************************//**
 * Check if TRNG unit was synthesized.
 *
 * @return 0 if TRNG was not synthesized, 1 if TRNG is available.
 **************************************************************************/
int neorv32_trng_available(void) {
 
  if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_TRNG)) {
    return 1;
  }
  else {
    return 0;
  }
}
 
 
/**********************************************************************//**
 * Enable true random number generator. The TRNG control register bits are listed in #NEORV32_TRNG_CT_enum.
 **************************************************************************/
void neorv32_trng_enable(void) {
 
  int i;
 
  TRNG_CT = 0; // reset
 
  for (i=0; i<1000; i++) {
    asm volatile ("nop");
  }
 
  TRNG_CT = 1 << TRNG_CT_EN; // activate
 
  for (i=0; i<1000; i++) {
    asm volatile ("nop");
  }
}
 
 
/**********************************************************************//**
 * Disable true random number generator.
 **************************************************************************/
void neorv32_trng_disable(void) {
 
  TRNG_CT &= ~((uint32_t)(1 << TRNG_CT_EN));
}
 
 
/**********************************************************************//**
 * Get random data from TRNG.
 *
 * @note The TRNG is automatically reset if a stuck-at-one/stuck-at-zero error is detected.
 *
 * @param[in,out] data uint8_t pointer for storing random data word
 * @return Data is valid when 0, stuck-at-zero error when 1, stuck-at-one error when 2, data not (yet) valid when 3
 **************************************************************************/
int neorv32_trng_get(uint8_t *data) {
 
  uint32_t trng_ct_reg = TRNG_CT;
 
  if (trng_ct_reg & (1<<TRNG_CT_ERROR_0)) { // stuck at zero error
    neorv32_trng_enable(); // reset TRNG
    return 1;
  }
 
  if (trng_ct_reg & (1<<TRNG_CT_ERROR_1)) { // stuck at one error
    neorv32_trng_enable(); // reset TRNG
    return 2;
  }
 
  if ((trng_ct_reg & (1<<TRNG_CT_VALID)) == 0) { // output data valid (yet)?
    return 3;
  }
 
  *data = (uint8_t)(trng_ct_reg >> TRNG_CT_DATA_LSB);
  return 0; // valid data
}
 

Line No.	Rev	Author	Line
1	2	zero_gravi	`// #################################################################################################`
2			`// # << NEORV32: neorv32_trng.c - True Random Number Generator (TRNG) HW Driver >> #`
3			`// # ********************************************************************************************* #`
4			`// # BSD 3-Clause License #`
5			`// # #`
6			`// # Copyright (c) 2020, Stephan Nolting. All rights reserved. #`
7			`// # #`
8			`// # Redistribution and use in source and binary forms, with or without modification, are #`
9			`// # permitted provided that the following conditions are met: #`
10			`// # #`
11			`// # 1. Redistributions of source code must retain the above copyright notice, this list of #`
12			`// # conditions and the following disclaimer. #`
13			`// # #`
14			`// # 2. Redistributions in binary form must reproduce the above copyright notice, this list of #`
15			`// # conditions and the following disclaimer in the documentation and/or other materials #`
16			`// # provided with the distribution. #`
17			`// # #`
18			`// # 3. Neither the name of the copyright holder nor the names of its contributors may be used to #`
19			`// # endorse or promote products derived from this software without specific prior written #`
20			`// # permission. #`
21			`// # #`
22			`// # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS #`
23			`// # OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF #`
24			`// # MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE #`
25			`// # COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, #`
26			`// # EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE #`
27			`// # GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED #`
28			`// # AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING #`
29			`// # NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED #`
30			`// # OF THE POSSIBILITY OF SUCH DAMAGE. #`
31			`// # ********************************************************************************************* #`
32			`// # The NEORV32 Processor - https://github.com/stnolting/neorv32 (c) Stephan Nolting #`
33			`// #################################################################################################`
34
35
36			`/********************************************************************//`
37			`* @file neorv32_trng.c`
38			`* @author Stephan Nolting`
39			`* @brief True Random Number Generator (TRNG) HW driver source file.`
40			`*`
41			`* @note These functions should only be used if the TRNG unit was synthesized (IO_TRNG_USE = true).`
42			`**************************************************************************/`
43
44			`#include "neorv32.h"`
45			`#include "neorv32_trng.h"`
46
47
48			`/********************************************************************//`
49			`* Check if TRNG unit was synthesized.`
50			`*`
51			`* @return 0 if TRNG was not synthesized, 1 if TRNG is available.`
52			`**************************************************************************/`
53			`int neorv32_trng_available(void) {`
54
55	12	zero_gravi	`if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_TRNG)) {`
56	2	zero_gravi	`return 1;`
57			`}`
58			`else {`
59			`return 0;`
60			`}`
61			`}`
62
63
64			`/********************************************************************//`
65	23	zero_gravi	`* Enable true random number generator. The TRNG control register bits are listed in #NEORV32_TRNG_CT_enum.`
66	2	zero_gravi	`**************************************************************************/`
67	23	zero_gravi	`void neorv32_trng_enable(void) {`
68	2	zero_gravi
69	23	zero_gravi	`int i;`
70
71	2	zero_gravi	`TRNG_CT = 0; // reset`
72
73	23	zero_gravi	`for (i=0; i<1000; i++) {`
74			`asm volatile ("nop");`
75			`}`
76	2	zero_gravi
77	23	zero_gravi	`TRNG_CT = 1 << TRNG_CT_EN; // activate`
78	2	zero_gravi
79	23	zero_gravi	`for (i=0; i<1000; i++) {`
80			`asm volatile ("nop");`
81	2	zero_gravi	`}`
82			`}`
83
84
85			`/********************************************************************//`
86			`* Disable true random number generator.`
87			`**************************************************************************/`
88			`void neorv32_trng_disable(void) {`
89
90			`TRNG_CT &= ~((uint32_t)(1 << TRNG_CT_EN));`
91			`}`
92
93
94			`/********************************************************************//`
95			`* Get random data from TRNG.`
96			`*`
97	23	zero_gravi	`* @note The TRNG is automatically reset if a stuck-at-one/stuck-at-zero error is detected.`
98			`*`
99			`* @param[in,out] data uint8_t pointer for storing random data word`
100			`* @return Data is valid when 0, stuck-at-zero error when 1, stuck-at-one error when 2, data not (yet) valid when 3`
101	2	zero_gravi	`**************************************************************************/`
102	23	zero_gravi	`int neorv32_trng_get(uint8_t *data) {`
103	2	zero_gravi
104	23	zero_gravi	`uint32_t trng_ct_reg = TRNG_CT;`
105	2	zero_gravi
106	23	zero_gravi	`if (trng_ct_reg & (1<<TRNG_CT_ERROR_0)) { // stuck at zero error`
107			`neorv32_trng_enable(); // reset TRNG`
108			`return 1;`
109			`}`
110	2	zero_gravi
111	23	zero_gravi	`if (trng_ct_reg & (1<<TRNG_CT_ERROR_1)) { // stuck at one error`
112			`neorv32_trng_enable(); // reset TRNG`
113			`return 2;`
114	2	zero_gravi	`}`
115
116	23	zero_gravi	`if ((trng_ct_reg & (1<<TRNG_CT_VALID)) == 0) { // output data valid (yet)?`
117			`return 3;`
118	2	zero_gravi	`}`
119
120	23	zero_gravi	`*data = (uint8_t)(trng_ct_reg >> TRNG_CT_DATA_LSB);`
121			`return 0; // valid data`
122	2	zero_gravi	`}`
123

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[/] [neorv32/] [trunk/] [sw/] [lib/] [source/] [neorv32_trng.c] - Blame information for rev 23