Ice_spi

Main SPI bus I/O. More...

Macros
#define	ICE_SPI_BAUDRATE   (33 * 1000 * 1000)
	This is chosen to allow all commands to the flash and SRAM to work. More...

Functions
void	ice_spi_init (void)
	Configure the GPIO pins of the SPI library to high-impedance. More...
void	ice_spi_init_cs_pin (uint8_t cs_pin, bool active_high)
void	ice_spi_chip_select (uint8_t cs_pin)
	Sets the SPI chip select pin to low state. More...
void	ice_spi_chip_deselect (uint8_t csn_pin)
	Sets the SPI chip select pin to high state. More...
void	ice_spi_write_async (const uint8_t *data, size_t data_size, void(*callback)(volatile void *), void *context)
	Wait previous transfer completion if any and enqueue a new one in the background (interrupt-driven). More...
void	ice_spi_write_blocking (const uint8_t *data, size_t data_size)
	Blocking version of ice_spi_write_async(). More...
void	ice_spi_read_async (uint8_t *data, size_t data_size, void(*callback)(volatile void *), void *context)
	Wait previous transfer completion if any and enqueue a new one in the background (interrupt-driven). More...
void	ice_spi_read_blocking (uint8_t *data, size_t data_size)
	Blocking version of ice_spi_read_async(). More...
bool	ice_spi_is_async_complete (void)
	Checks for compmletion of the current async operation. More...
void	ice_spi_wait_completion (void)
	Waits until SPI transfer commpletes.

Detailed Description

Main SPI bus I/O.

SPI library exclusive to the main SPI bus between the RP2040 and the various other board components, including the iCE40 CRAM, iCE40 hardened SPI core, SRAM chip, FLASH chip.

Macro Definition Documentation

ICE_SPI_BAUDRATE

#define ICE_SPI_BAUDRATE   (33 * 1000 * 1000)

This is chosen to allow all commands to the flash and SRAM to work.

33MHz is the fastest the SRAM supports a 03h read command.

Function Documentation

ice_spi_chip_deselect()

void ice_spi_chip_deselect

(

uint8_t

csn_pin

)

Sets the SPI chip select pin to high state.

Parameters

csn_pin

User-selectable GPIO pin to assert, set to LOW voltage level.

Also set the SPI TX and SCK pins back to input/high-z mode.

ice_spi_chip_select()

void ice_spi_chip_select

(

uint8_t

cs_pin

)

Sets the SPI chip select pin to low state.

Parameters

csn_pin	User-selectable GPIO pin to assert, set to LOW voltage level.
active_high	true for active-high chip-select pin, false for active-low.

Also set the SPI TX and SCK pins to output/drive mode, and keeps the RX pin to input/high-z mode.

ice_spi_init()

void ice_spi_init

(

void

)

Configure the GPIO pins of the SPI library to high-impedance.

This lets others access the bus, such as the iCE40 during initial configuration.

ice_spi_is_async_complete()

bool ice_spi_is_async_complete

(

void

)

Checks for compmletion of the current async operation.

Returns

True if an SPI transfer is ongoing, false if ready to enqueue another.

ice_spi_read_async()

void ice_spi_read_async	(	uint8_t *	data,
		size_t	data_size,
		void(*)(volatile void *)	callback,
		void *	context
	)

Wait previous transfer completion if any and enqueue a new one in the background (interrupt-driven).

Parameters

tx	Byte to send conotinuously while readying
buf	Buffer to fill from SPI.
len	Size of that buffer.
callback	Function called at the end of the transfer.
context	Argument passed to that function.

If callback is NULL, then nothing will be done.

ice_spi_read_blocking()

void ice_spi_read_blocking	(	uint8_t *	data,
		size_t	data_size
	)

Blocking version of ice_spi_read_async().

Parameters

tx	Byte to send conotinuously while readying
buf	Buffer to fill from SPI.
len	Size of that buffer.

ice_spi_write_async()

void ice_spi_write_async	(	const uint8_t *	data,
		size_t	data_size,
		void(*)(volatile void *)	callback,
		void *	context
	)

Wait previous transfer completion if any and enqueue a new one in the background (interrupt-driven).

Parameters

buf	buffer to send over SPI.
len	size of that buffer.
callback	function called at the end of the transfer.
context	argument passed to that function.

If callback is NULL, then nothing will be done.

ice_spi_write_blocking()

void ice_spi_write_blocking	(	const uint8_t *	data,
		size_t	data_size
	)

Blocking version of ice_spi_write_async().

Parameters

buf	Buffer to send over SPI.
len	Size of that buffer.