Detailed Description

TRNG driver implementation for the CC26XX family.

============================================================================

Warning: This is a beta API. It may change in future releases.

This file should only be included in the board file to fill the TRNG_config struct.

The CC26XX family has a dedicated hardware TRNG based on sampling multiple free running oscillators. With all FROs enabled, the TRNG hardware generates 64 bits of entropy approximately every 5ms. The driver implementation chains multiple 64-bit entropy generation operations together to generate an arbitrary amount of entropy.

The driver implementation does not perform runtime checks for most input parameters. Only values that are likely to have a stochastic element to them are checked (such as whether a driver is already open). Higher input paramter validation coverage is achieved by turning on assertions when compiling the driver.

#include <stdint.h>
#include <stdbool.h>
#include <ti/drivers/Power.h>
#include <ti/drivers/TRNG.h>
#include <ti/drivers/cryptoutils/cryptokey/CryptoKey.h>
#include <ti/drivers/dpl/HwiP.h>
#include <ti/drivers/dpl/SwiP.h>
#include <ti/drivers/dpl/SemaphoreP.h>

Include dependency graph for TRNGCC26XX.h:

Go to the source code of this file.

Data Structures
struct	TRNGCC26XX_HWAttrs
	TRNGCC26XX Hardware Attributes. More...

struct	TRNGCC26XX_Object
	TRNGCC26XX Object. More...

Macros
#define	TRNGCC26XX_SAMPLES_PER_CYCLE_MIN 256
	Minimum random samples for each entropy generation call. More...

#define	TRNGCC26XX_SAMPLES_PER_CYCLE_DEFAULT 240000
	Default random samples for each entropy generation call. More...

#define	TRNGCC26XX_SAMPLES_PER_CYCLE_MAX 16777216
	Maximum random samples for each entropy generation call. More...

#define	TRNGCC26XX_MIN_BYTES_PER_ITERATION 8
	Minimum number of bytes provided by the TRNG hardware in one go. Smaller amounts can by requested in driver calls but the full number will always be generated. Part of the generated entropy will simply not be copied back to the target buffer if the requested length is not a multiple of TRNGCC26XX_MIN_BYTES_PER_ISR. More...

Typedefs
typedef struct TRNGCC26XX_HWAttrs	TRNGCC26XX_HWAttrs
	TRNGCC26XX Hardware Attributes. More...

typedef struct TRNGCC26XX_Object	TRNGCC26XX_Object
	TRNGCC26XX Object. More...

Functions
int_fast16_t	TRNGCC26XX_setSamplesPerCycle (TRNG_Handle handle, uint32_t samplesPerCycle)
	Sets the number of entropy generation cycles before the results are returned. More...

TRNG_Handle	TRNGCC26XX_construct (TRNG_Config config, const TRNG_Params params)

Macro Definition Documentation

§ TRNGCC26XX_SAMPLES_PER_CYCLE_MIN

#define TRNGCC26XX_SAMPLES_PER_CYCLE_MIN 256

Minimum random samples for each entropy generation call.

§ TRNGCC26XX_SAMPLES_PER_CYCLE_DEFAULT

#define TRNGCC26XX_SAMPLES_PER_CYCLE_DEFAULT 240000

Default random samples for each entropy generation call.

Set to generate 64 bits of randomness in 5ms with all FROs active.

§ TRNGCC26XX_SAMPLES_PER_CYCLE_MAX

#define TRNGCC26XX_SAMPLES_PER_CYCLE_MAX 16777216

Maximum random samples for each entropy generation call.

§ TRNGCC26XX_MIN_BYTES_PER_ITERATION

#define TRNGCC26XX_MIN_BYTES_PER_ITERATION 8

Minimum number of bytes provided by the TRNG hardware in one go. Smaller amounts can by requested in driver calls but the full number will always be generated. Part of the generated entropy will simply not be copied back to the target buffer if the requested length is not a multiple of TRNGCC26XX_MIN_BYTES_PER_ISR.

Typedef Documentation

§ TRNGCC26XX_HWAttrs

typedef struct TRNGCC26XX_HWAttrs TRNGCC26XX_HWAttrs

TRNGCC26XX Hardware Attributes.

TRNG26X0 hardware attributes should be included in the board file and pointed to by the TRNG_config struct.

§ TRNGCC26XX_Object

typedef struct TRNGCC26XX_Object TRNGCC26XX_Object

TRNGCC26XX Object.

The application must not access any member variables of this structure!

Function Documentation

§ TRNGCC26XX_setSamplesPerCycle()

int_fast16_t TRNGCC26XX_setSamplesPerCycle	(	TRNG_Handle	handle,
		uint32_t	samplesPerCycle
	)

Sets the number of entropy generation cycles before the results are returned.

The default value is set to generate 64 bits of entropy.

Precondition: TRNG_open() has to be called first successfully

Parameters

handle	A TRNGCC26XX handle returned from TRNGCC26XX_open
samplesPerCycle	Number of 48MHz clock cycles to sample. Must be between 2^8 and 2^24.

See also: TRNG_open()

§ TRNGCC26XX_construct()

TRNG_Handle TRNGCC26XX_construct	(	TRNG_Config *	config,
		const TRNG_Params *	params
	)