neorv32_twi.h File Reference

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

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Data Structures
struct	neorv32_twi_t

Functions
Prototypes
int	neorv32_twi_available (void)
void	neorv32_twi_setup (int prsc, int cdiv, int csen)
void	neorv32_twi_disable (void)
void	neorv32_twi_enable (void)
void	neorv32_twi_mack_enable (void)
void	neorv32_twi_mack_disable (void)
int	neorv32_twi_busy (void)
int	neorv32_twi_start_trans (uint8_t a)
int	neorv32_twi_trans (uint8_t d)
uint8_t	neorv32_twi_get_data (void)
void	neorv32_twi_generate_stop (void)
void	neorv32_twi_generate_start (void)
int	neorv32_twi_bus_claimed (void)

IO Device: Two-Wire Interface Controller (TWI)
#define	NEORV32_TWI   ((neorv32_twi_t*) (NEORV32_TWI_BASE))
enum	NEORV32_TWI_CTRL_enum {   TWI_CTRL_EN = 0 , TWI_CTRL_START = 1 , TWI_CTRL_STOP = 2 , TWI_CTRL_MACK = 3 ,   TWI_CTRL_CSEN = 4 , TWI_CTRL_PRSC0 = 5 , TWI_CTRL_PRSC1 = 6 , TWI_CTRL_PRSC2 = 7 ,   TWI_CTRL_CDIV0 = 8 , TWI_CTRL_CDIV1 = 9 , TWI_CTRL_CDIV2 = 10 , TWI_CTRL_CDIV3 = 11 ,   TWI_CTRL_CLAIMED = 29 , TWI_CTRL_ACK = 30 , TWI_CTRL_BUSY = 31 }
enum	NEORV32_TWI_DATA_enum { TWI_DATA_LSB = 0 , TWI_DATA_MSB = 7 }

Detailed Description

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

Note

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

Macro Definition Documentation

NEORV32_TWI

#define NEORV32_TWI   ((neorv32_twi_t*) (NEORV32_TWI_BASE))

TWI module hardware access (neorv32_twi_t)

Enumeration Type Documentation

NEORV32_TWI_CTRL_enum

enum NEORV32_TWI_CTRL_enum

TWI control register bits

Enumerator
TWI_CTRL_EN	TWI control register(0) (r/w): TWI enable
TWI_CTRL_START	TWI control register(1) (-/w): Generate START condition, auto-clears
TWI_CTRL_STOP	TWI control register(2) (-/w): Generate STOP condition, auto-clears
TWI_CTRL_MACK	TWI control register(3) (r/w): Generate ACK by controller for each transmission
TWI_CTRL_CSEN	TWI control register(4) (r/w): Allow clock stretching when set
TWI_CTRL_PRSC0	TWI control register(5) (r/w): Clock prescaler select bit 0
TWI_CTRL_PRSC1	TWI control register(6) (r/w): Clock prescaler select bit 1
TWI_CTRL_PRSC2	TWI control register(7) (r/w): Clock prescaler select bit 2
TWI_CTRL_CDIV0	TWI control register(8) (r/w): Clock divider bit 0
TWI_CTRL_CDIV1	TWI control register(9) (r/w): Clock divider bit 1
TWI_CTRL_CDIV2	TWI control register(10) (r/w): Clock divider bit 2
TWI_CTRL_CDIV3	TWI control register(11) (r/w): Clock divider bit 3
TWI_CTRL_CLAIMED	TWI control register(29) (r/-): Set if the TWI bus is currently claimed by any controller
TWI_CTRL_ACK	TWI control register(30) (r/-): ACK received when set
TWI_CTRL_BUSY	TWI control register(31) (r/-): Transfer in progress, busy flag

NEORV32_TWI_DATA_enum

enum NEORV32_TWI_DATA_enum

TWI receive/transmit data register bits

Enumerator
TWI_DATA_LSB	TWI data register(0) (r/w): Receive/transmit data (8-bit) LSB
TWI_DATA_MSB	TWI data register(7) (r/w): Receive/transmit data (8-bit) MSB

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_bus_claimed()

int neorv32_twi_bus_claimed

(

void

)

Check if the TWI bus is currently claimed by any controller.

Returns

0: 0 if bus is not claimed, 1 if bus is claimed.

neorv32_twi_busy()

int neorv32_twi_busy

(

void

)

Check if TWI is busy.

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_stop()

void neorv32_twi_generate_stop

(

void

)

Generate STOP condition.

Note

Blocking function.

neorv32_twi_get_data()

uint8_t neorv32_twi_get_data

(

void

)

Get received data from last transmission.

Returns

0: Last received data byte.

neorv32_twi_mack_disable()

void neorv32_twi_mack_disable

(

void

)

Deactivate sending ACKs by controller (MACK).

neorv32_twi_mack_enable()

void neorv32_twi_mack_enable

(

void

)

Activate sending ACKs by controller (MACK).

neorv32_twi_setup()

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

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]	csen	Allow clock stretching when 1.

neorv32_twi_start_trans()

int neorv32_twi_start_trans

(

uint8_t

a

)

Generate START condition and send first byte (address including R/W bit).

Note

Blocking function.

Parameters

[in]

a

Data byte including 7-bit address and R/W-bit (lsb).

Returns

0: ACK received, 1: NACK received.

neorv32_twi_trans()

int neorv32_twi_trans

(

uint8_t

d

)

Send data byte and also receive data byte (can be read via neorv32_twi_get_data()).

Note

Blocking function.

Parameters

[in]

d

Data byte to be send.

Returns

0: ACK received, 1: NACK received.