neorv32_xip.c File Reference

Execute in place module (XIP) HW driver source file. More...

#include "neorv32.h"
#include "neorv32_xip.h"

Functions
int	neorv32_xip_available (void)
int	neorv32_xip_setup (uint8_t prsc, uint8_t cpol, uint8_t cpha, uint8_t rd_cmd)
int	neorv32_xip_start (uint8_t abytes, uint32_t page_base)
void	neorv32_xip_highspeed_enable (void)
void	neorv32_xip_highspeed_disable (void)
void	neorv32_xip_burst_mode_enable (void)
void	neorv32_xip_burst_mode_disable (void)
int	neorv32_xip_spi_trans (uint8_t nbytes, uint64_t *rtx_data)

Detailed Description

Execute in place module (XIP) HW driver source file.

Note

These functions should only be used if the XIP module was synthesized (IO_XIP_EN = true).

Function Documentation

neorv32_xip_available()

int neorv32_xip_available

(

void

)

Check if XIP module was synthesized.

Returns

0 if XIP was not synthesized, 1 if XIP is available.

neorv32_xip_burst_mode_disable()

void neorv32_xip_burst_mode_disable

(

void

)

Disable XIP burst mode.

neorv32_xip_burst_mode_enable()

void neorv32_xip_burst_mode_enable

(

void

)

Enable XIP burst mode (incremental reads).

Note

Make sure your flash supports this feature (most flash chips do so).

neorv32_xip_highspeed_disable()

void neorv32_xip_highspeed_disable

(

void

)

Disable high-speed SPI mode.

neorv32_xip_highspeed_enable()

void neorv32_xip_highspeed_enable

(

void

)

Enable high-speed SPI mode (running at half of the processor clock).

Note

High-speed SPI mode ignores the programmed clock prescaler configuration.

neorv32_xip_setup()

int neorv32_xip_setup	(	uint8_t	prsc,
		uint8_t	cpol,
		uint8_t	cpha,
		uint8_t	rd_cmd
	)

Configure XIP module: configure SPI/flash properties.

Warning

This will reset the XIP module overriding the CTRL register.

Note

This function will also send 64 dummy clocks via the SPI port (with chip-select disabled).

Parameters

[in]	prsc	SPI clock prescaler select (0..7).
[in]	cpol	SPI clock polarity (0/1).
[in]	cpha	SPI clock phase(0/1).
[in]	rd_cmd	SPI flash read byte command.

Returns

0 if configuration is OK, -1 if configuration error.

neorv32_xip_spi_trans()

int neorv32_xip_spi_trans	(	uint8_t	nbytes,
		uint64_t *	rtx_data
	)

Direct SPI access to the XIP flash.

Warning

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

Note

This function is blocking.

Parameters

[in]	nbytes	Number of bytes to transfer (1..8).
[in,out]	rtx_data	Pointer to 64-bit TX/RX data (MSB-aligned for sending, LSB-aligned for receiving (only 32-bit)).

Returns

0 if valid transfer, 1 if transfer configuration error.

neorv32_xip_start()

int neorv32_xip_start	(	uint8_t	abytes,
		uint32_t	page_base
	)

Enable XIP mode (to allow CPU to transparently fetch data & instructions).

Parameters

[in]	abytes	Number of address bytes used to access the SPI flash (1,2,3,4).
[in]	page_base	XIP memory page base address (top 4 address bits, 0..15).

Returns

0 if XIP configuration is OK, -1 if configuration error.