| Line 50... |
Line 50... |
*
|
*
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* @return 0 if TRNG was not synthesized, 1 if TRNG is available.
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* @return 0 if TRNG was not synthesized, 1 if TRNG is available.
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**************************************************************************/
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**************************************************************************/
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int neorv32_trng_available(void) {
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int neorv32_trng_available(void) {
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|
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if (SYSINFO_FEATURES & (1 << SYSINFO_FEATURES_IO_TRNG)) {
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if (NEORV32_SYSINFO.SOC & (1 << SYSINFO_SOC_IO_TRNG)) {
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return 1;
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return 1;
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}
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}
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else {
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else {
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return 0;
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return 0;
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}
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}
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}
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}
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|
|
|
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/**********************************************************************//**
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/**********************************************************************//**
|
* Enable true random number generator. The TRNG control register bits are listed in #NEORV32_TRNG_CT_enum.
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* Enable true random number generator. The TRNG control register bits are listed in #NEORV32_TRNG_CTRL_enum.
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**************************************************************************/
|
**************************************************************************/
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void neorv32_trng_enable(void) {
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void neorv32_trng_enable(void) {
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|
|
int i;
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int i;
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|
|
TRNG_CT = 0; // reset
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NEORV32_TRNG.CTRL = 0; // reset
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|
|
for (i=0; i<256; i++) {
|
for (i=0; i<256; i++) {
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asm volatile ("nop");
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asm volatile ("nop");
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}
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}
|
|
|
TRNG_CT = 1 << TRNG_CT_EN; // activate
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NEORV32_TRNG.CTRL = 1 << TRNG_CTRL_EN; // activate
|
|
|
for (i=0; i<256; i++) {
|
for (i=0; i<256; i++) {
|
asm volatile ("nop");
|
asm volatile ("nop");
|
}
|
}
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}
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}
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| Line 85... |
Line 85... |
/**********************************************************************//**
|
/**********************************************************************//**
|
* Disable true random number generator.
|
* Disable true random number generator.
|
**************************************************************************/
|
**************************************************************************/
|
void neorv32_trng_disable(void) {
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void neorv32_trng_disable(void) {
|
|
|
TRNG_CT = 0;
|
NEORV32_TRNG.CTRL = 0;
|
}
|
}
|
|
|
|
|
/**********************************************************************//**
|
/**********************************************************************//**
|
* Get random data byte from TRNG.
|
* Get random data byte from TRNG.
|
| Line 102... |
Line 102... |
const int retries = 3;
|
const int retries = 3;
|
int i;
|
int i;
|
uint32_t ct_reg;
|
uint32_t ct_reg;
|
|
|
for (i=0; i<retries; i++) {
|
for (i=0; i<retries; i++) {
|
ct_reg = TRNG_CT;
|
ct_reg = NEORV32_TRNG.CTRL;
|
|
|
if ((ct_reg & (1<<TRNG_CT_VALID)) == 0) { // output data valid?
|
if ((ct_reg & (1<<TRNG_CTRL_VALID)) == 0) { // output data valid?
|
continue;
|
continue;
|
}
|
}
|
|
|
*data = (uint8_t)(ct_reg >> TRNG_CT_DATA_LSB);
|
*data = (uint8_t)(ct_reg >> TRNG_CTRL_DATA_LSB);
|
return 0; // valid data
|
return 0; // valid data
|
}
|
}
|
|
|
return -1; // no valid data available
|
return -1; // no valid data available
|
}
|
}
|
