neorv32_twi.c File Reference

Two-Wire Interface Controller (TWI) HW driver source file. More...

#include <neorv32.h>

Functions
int	neorv32_twi_available (void)
void	neorv32_twi_setup (int prsc, int cdiv, int clkstr)
int	neorv32_twi_get_fifo_depth (void)
void	neorv32_twi_disable (void)
void	neorv32_twi_enable (void)
int	neorv32_twi_sense_scl (void)
int	neorv32_twi_sense_sda (void)
int	neorv32_twi_busy (void)
int	neorv32_twi_get (uint8_t *data)
int	neorv32_twi_trans (uint8_t *data, int mack)
void	neorv32_twi_generate_stop (void)
void	neorv32_twi_generate_start (void)
void	neorv32_twi_send_nonblocking (uint8_t data, int mack)
void	neorv32_twi_generate_stop_nonblocking (void)
void	neorv32_twi_generate_start_nonblocking (void)

Detailed Description

Two-Wire Interface Controller (TWI) HW driver source file.

Note

These functions should only be used if the TWI unit was synthesized (IO_TWI_EN = true).

See also

https://stnolting.github.io/neorv32/sw/files.html

Function Documentation

neorv32_twi_available()

int neorv32_twi_available

(

void

)

Check if TWI unit was synthesized.

Returns

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

neorv32_twi_busy()

int neorv32_twi_busy

(

void

)

Check if TWI controller is busy (TWI bus engine busy or TX FIFO not empty).

Returns

0 if idle, 1 if busy

neorv32_twi_disable()

void neorv32_twi_disable

(

void

)

Disable TWI controller.

neorv32_twi_enable()

void neorv32_twi_enable

(

void

)

Enable TWI controller.

neorv32_twi_generate_start()

void neorv32_twi_generate_start

(

void

)

Generate START (or REPEATED-START) condition.

Note

Blocking function.

neorv32_twi_generate_start_nonblocking()

void neorv32_twi_generate_start_nonblocking

(

void

)

Generate START (or REPEATED-START) condition.

Note

Non-blocking function; does not check the TX FIFO.

neorv32_twi_generate_stop()

void neorv32_twi_generate_stop

(

void

)

Generate STOP condition.

Note

Blocking function.

neorv32_twi_generate_stop_nonblocking()

void neorv32_twi_generate_stop_nonblocking

(

void

)

Generate STOP condition.

Note

Non-blocking function; does not check the TX FIFO.

neorv32_twi_get()

int neorv32_twi_get

(

uint8_t *

data

)

Get received data + ACK/NACH from RX FIFO.

Parameters

[in,out]

data

Pointer for returned data (uint8_t).

Returns

RX FIFO access status (-1 = no data available, 0 = ACK received, 1 = NACK received).

neorv32_twi_get_fifo_depth()

int neorv32_twi_get_fifo_depth

(

void

)

Get TWI FIFO depth.

Returns

FIFO depth (number of entries), zero if no FIFO implemented

neorv32_twi_send_nonblocking()

void neorv32_twi_send_nonblocking	(	uint8_t	data,
		int	mack )

Send data byte (RX can be read via neorv32_twi_get()).

Note

Non-blocking function; does not check the TX FIFO.

Parameters

[in]	data	Data byte to be send.
[in]	mack	Generate ACK by host controller when set.

neorv32_twi_sense_scl()

int neorv32_twi_sense_scl

(

void

)

Get current state of SCL bus line.

Returns

1 if SCL is high, 0 if SCL is low.

neorv32_twi_sense_sda()

int neorv32_twi_sense_sda

(

void

)

Get current state of SDA bus line.

Returns

1 if SDA is high, 0 if SDA is low.

neorv32_twi_setup()

void neorv32_twi_setup	(	int	prsc,
		int	cdiv,
		int	clkstr )

Enable and configure TWI controller. The TWI control register bits are listed in NEORV32_TWI_CTRL_enum.

Parameters

[in]	prsc	Clock prescaler select (0..7). See NEORV32_CLOCK_PRSC_enum.
[in]	cdiv	Clock divider (0..15).
[in]	clkstr	Enable (allow) clock stretching.

neorv32_twi_trans()

int neorv32_twi_trans	(	uint8_t *	data,
		int	mack )

TWI transfer: send data byte and also receive data byte.

Note

Blocking function.

Parameters

[in,out]	data	Pointer for TX/RX data (uint8_t).
[in]	mack	Generate ACK by host controller when set.

Returns

0: ACK received, 1: NACK received.