main.c File Reference

Example program showing how to use the CFU's custom instructions (XTEA example). More...

#include <neorv32.h>

Macros
User configuration
#define	BAUD_RATE   19200
#define	XTEA_CYCLES   20
#define	DATA_NUM   64
Define macros for easy custom instruction wrapping
#define	xtea_hw_init(sum)   neorv32_cfu_r3_instr(0b0000000, 0b100, sum, 0)
#define	xtea_hw_enc_v0_step(v0, v1)   neorv32_cfu_r3_instr(0b0000000, 0b000, v0, v1)
#define	xtea_hw_enc_v1_step(v0, v1)   neorv32_cfu_r3_instr(0b0000000, 0b001, v0, v1)
#define	xtea_hw_dec_v0_step(v0, v1)   neorv32_cfu_r3_instr(0b0000000, 0b010, v0, v1)
#define	xtea_hw_dec_v1_step(v0, v1)   neorv32_cfu_r3_instr(0b0000000, 0b011, v0, v1)

Functions
uint32_t	xorshift32 (void)
void	xtea_sw_encipher (uint32_t num_cycles, uint32_t *v, const uint32_t k[4])
void	xtea_sw_decipher (unsigned int num_cycles, uint32_t *v, const uint32_t k[4])
int	main ()

Variables
Global variables
const uint32_t	xtea_delta = 0x9e3779b9
const uint32_t	key [4] = {0x207230ba, 0x1ffba710, 0xc45271ef, 0xdd01768a}
uint32_t	input_data [DATA_NUM]
uint32_t	cypher_data_sw [DATA_NUM]
uint32_t	cypher_data_hw [DATA_NUM]
uint32_t	plain_data_sw [DATA_NUM]
uint32_t	plain_data_hw [DATA_NUM]
uint32_t	time_enc_sw
uint32_t	time_enc_hw
uint32_t	time_dec_sw
uint32_t	time_dec_hw

Detailed Description

Example program showing how to use the CFU's custom instructions (XTEA example).

Author

Stephan Nolting

Note

Take a look at the highly-commented "hardware-counterpart" of this CFU example in 'rtl/core/neorv32_cpu_cp_cfu.vhd'.

Macro Definition Documentation

BAUD_RATE

#define BAUD_RATE   19200

UART BAUD rate

DATA_NUM

#define DATA_NUM   64

Input data size (in number of 32-bit words), has to be even

XTEA_CYCLES

#define XTEA_CYCLES   20

Number XTEA cycles

Function Documentation

main()

int main

(

void

)

Main function: run pure-SW XTEA and compare with HW-XTEA

Note

This program requires the CFU, UART0 and the Zicntr ISA extension.

Returns

0 if execution was successful

xorshift32()

uint32_t xorshift32

(

void

)

Pseudo-random number generator (to generate deterministic test data).

Returns

Random data (32-bit).

xtea_sw_decipher()

void xtea_sw_decipher	(	unsigned int	num_cycles,
		uint32_t *	v,
		const uint32_t	k[4] )

XTEA decryption - software reference

Source: https://de.wikipedia.org/wiki/Extended_Tiny_Encryption_Algorithm

Parameters

[in]	num_cycles	Number of encryption cycles.
[in,out]	v	Decryption data/result array (2x32-bit).
[in]	k	Decryption key array (4x32-bit).

xtea_sw_encipher()

void xtea_sw_encipher	(	uint32_t	num_cycles,
		uint32_t *	v,
		const uint32_t	k[4] )

XTEA encryption - software reference

Source: https://de.wikipedia.org/wiki/Extended_Tiny_Encryption_Algorithm

Parameters

[in]	num_cycles	Number of encryption cycles.
[in,out]	v	Encryption data/result array (2x32-bit).
[in]	k	Encryption key array (4x32-bit).

Variable Documentation

cypher_data_hw

uint32_t cypher_data_hw[DATA_NUM]

XTEA delta (round-key update)

cypher_data_sw

uint32_t cypher_data_sw[DATA_NUM]

Encryption results

input_data

uint32_t input_data[DATA_NUM]

Encryption input data

key

const uint32_t key[4] = {0x207230ba, 0x1ffba710, 0xc45271ef, 0xdd01768a}

Encryption/decryption key (128-bit)

plain_data_hw

uint32_t plain_data_hw[DATA_NUM]

XTEA delta (round-key update)

plain_data_sw

uint32_t plain_data_sw[DATA_NUM]

Decryption results

time_dec_hw

uint32_t time_dec_hw

XTEA delta (round-key update)

time_dec_sw

uint32_t time_dec_sw

XTEA delta (round-key update)

time_enc_hw

uint32_t time_enc_hw

XTEA delta (round-key update)

time_enc_sw

uint32_t time_enc_sw

Timing data

xtea_delta

const uint32_t xtea_delta = 0x9e3779b9

XTEA delta (round-key update)