Demo for the the execute in place (XIP) module. More...

#include <neorv32.h>

Macros
User configuration
#define	BAUD_RATE 19200

#define	XIP_PAGE_BASE_ADDR 0x40000000

#define	FLASH_BASE 0x00400000

#define	FLASH_ABYTES 3

#define	XIP_CLK_PRSC CLK_PRSC_128

Enumerations
enum	SPI_FLASH_CMD { SPI_FLASH_CMD_WRITE = 0x02 , SPI_FLASH_CMD_READ = 0x03 , SPI_FLASH_CMD_READ_STATUS = 0x05 , SPI_FLASH_CMD_WRITE_ENABLE = 0x06 , SPI_FLASH_CMD_SECTOR_ERASE = 0xD8 }

Functions
Prototypes
int	erase_sector_xip_flash (uint32_t base_addr)

int	program_xip_flash (uint32_t *src, uint32_t base_addr, uint32_t size)

Simple demo program to be stored to the XIP flash.
Note This is a the "raw HEX version" from the rv32i-only "sw/example/demo_blink_led" demo program (using "make clean_all hex"). This program has been compiled using a modified linker script: rom ORIGIN = XIP base page + flash base address (= XIP_PAGE_BASE_ADDR + FLASH_BASE)
const uint32_t	xip_program []

int	main ()

Detailed Description

Demo for the the execute in place (XIP) module.

Author: Stephan Nolting

Macro Definition Documentation

◆ BAUD_RATE

#define BAUD_RATE 19200

UART BAUD rate

◆ FLASH_ABYTES

#define FLASH_ABYTES 3

Flash address bytes

◆ FLASH_BASE

#define FLASH_BASE 0x00400000

Flash base address (32-bit)

◆ XIP_CLK_PRSC

#define XIP_CLK_PRSC CLK_PRSC_128

XIP SPI clock prescaler select

◆ XIP_PAGE_BASE_ADDR

#define XIP_PAGE_BASE_ADDR 0x40000000

XIP page base address (32-bit)

Enumeration Type Documentation

◆ SPI_FLASH_CMD

enum SPI_FLASH_CMD

SPI flash commands

Enumerator
SPI_FLASH_CMD_WRITE	Write data
SPI_FLASH_CMD_READ	Read data
SPI_FLASH_CMD_READ_STATUS	Get status register
SPI_FLASH_CMD_WRITE_ENABLE	Allow write access
SPI_FLASH_CMD_SECTOR_ERASE	Erase complete sector

Function Documentation

◆ erase_sector_xip_flash()

int erase_sector_xip_flash ( uint32_t base_addr )

Erase sector starting at base address.

Parameters

[in] base_addr Base address of sector to erase.

◆ main()

int main ( void )

Main function: configure the XIP module, program a small program to the attached flash and run that program from there. The program shows an incrementing counter at the lowest 8-bits of the GPIO output port. This demo is meant for a SPI flash/EEPROM with 16-bit addresses.

Note: This program requires the XIP module, UART0 and the GPIO module.

Returns: 0 if execution was successful

◆ program_xip_flash()

int program_xip_flash	(	uint32_t *	src,
		uint32_t	base_addr,
		uint32_t	size
	)

Helper function to program the XIP flash via the direct SPI feature of the XIP module.

Warning: This function can only be used BEFORE the XIP-mode is activated!

Note: This function is blocking and performs individual writes for each byte (little-endian byte order!).