neorv32_xip.h File Reference

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

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Data Structures
struct	neorv32_xip_t

Functions
Prototypes
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)

IO Device: Execute In Place Module (XIP)
#define	NEORV32_XIP   ((neorv32_xip_t*) (NEORV32_XIP_BASE))
enum	NEORV32_XIP_CTRL_enum {   XIP_CTRL_EN = 0 , XIP_CTRL_PRSC0 = 1 , XIP_CTRL_PRSC1 = 2 , XIP_CTRL_PRSC2 = 3 ,   XIP_CTRL_CPOL = 4 , XIP_CTRL_CPHA = 5 , XIP_CTRL_SPI_NBYTES_LSB = 6 , XIP_CTRL_SPI_NBYTES_MSB = 9 ,   XIP_CTRL_XIP_EN = 10 , XIP_CTRL_XIP_ABYTES_LSB = 11 , XIP_CTRL_XIP_ABYTES_MSB = 12 , XIP_CTRL_RD_CMD_LSB = 13 ,   XIP_CTRL_RD_CMD_MSB = 20 , XIP_CTRL_PAGE_LSB = 21 , XIP_CTRL_PAGE_MSB = 24 , XIP_CTRL_SPI_CSEN = 25 ,   XIP_CTRL_HIGHSPEED = 26 , XIP_CTRL_BURST_EN = 27 , XIP_CTRL_PHY_BUSY = 30 , XIP_CTRL_XIP_BUSY = 31 }

Detailed Description

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

Note

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

Macro Definition Documentation

NEORV32_XIP

#define NEORV32_XIP   ((neorv32_xip_t*) (NEORV32_XIP_BASE))

XIP module hardware access (neorv32_xip_t)

Enumeration Type Documentation

NEORV32_XIP_CTRL_enum

enum NEORV32_XIP_CTRL_enum

XIP control/data register bits

Enumerator
XIP_CTRL_EN	XIP control register( 0) (r/w): XIP module enable
XIP_CTRL_PRSC0	XIP control register( 1) (r/w): Clock prescaler select bit 0
XIP_CTRL_PRSC1	XIP control register( 2) (r/w): Clock prescaler select bit 1
XIP_CTRL_PRSC2	XIP control register( 3) (r/w): Clock prescaler select bit 2
XIP_CTRL_CPOL	XIP control register( 4) (r/w): SPI (idle) clock polarity
XIP_CTRL_CPHA	XIP control register( 5) (r/w): SPI clock phase
XIP_CTRL_SPI_NBYTES_LSB	XIP control register( 6) (r/w): Number of bytes in SPI transmission, LSB
XIP_CTRL_SPI_NBYTES_MSB	XIP control register( 9) (r/w): Number of bytes in SPI transmission, MSB
XIP_CTRL_XIP_EN	XIP control register(10) (r/w): XIP access enable
XIP_CTRL_XIP_ABYTES_LSB	XIP control register(11) (r/w): Number XIP address bytes (minus 1), LSB
XIP_CTRL_XIP_ABYTES_MSB	XIP control register(12) (r/w): Number XIP address bytes (minus 1), MSB
XIP_CTRL_RD_CMD_LSB	XIP control register(13) (r/w): SPI flash read command, LSB
XIP_CTRL_RD_CMD_MSB	XIP control register(20) (r/w): SPI flash read command, MSB
XIP_CTRL_PAGE_LSB	XIP control register(21) (r/w): XIP memory page, LSB
XIP_CTRL_PAGE_MSB	XIP control register(24) (r/w): XIP memory page, MSB
XIP_CTRL_SPI_CSEN	XIP control register(25) (r/w): SPI chip-select enable
XIP_CTRL_HIGHSPEED	XIP control register(26) (r/w): SPI high-speed mode enable (ignoring XIP_CTRL_PRSC)
XIP_CTRL_BURST_EN	XIP control register(27) (r/w): Enable XIP burst mode
XIP_CTRL_PHY_BUSY	XIP control register(20) (r/-): SPI PHY is busy
XIP_CTRL_XIP_BUSY	XIP control register(31) (r/-): XIP access in progress

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.