Global API

Functions for creating, configuring, and destroying an epio instance. More...

Functions
EPIO_EXPORT epio_t *	epio_init (void)
	Create and initialise a new epio instance.
EPIO_EXPORT void	epio_free (epio_t *epio)
	Free an epio instance and all associated resources.
EPIO_EXPORT void	epio_set_sm_debug (epio_t *epio, uint8_t block, uint8_t sm, epio_sm_debug_t *debug)
	Sets debug information for a specific state machine.
EPIO_EXPORT void	epio_get_sm_debug (epio_t *epio, uint8_t block, uint8_t sm, epio_sm_debug_t *debug)
	Gets the debug information for a specific state machine.
EPIO_EXPORT void	epio_set_gpiobase (epio_t *epio, uint8_t block, uint32_t gpio_base)
	Set the GPIO base for a PIO block.
EPIO_EXPORT uint32_t	epio_get_gpiobase (epio_t *epio, uint8_t block)
	Get the GPIO base for a PIO block.
EPIO_EXPORT void	epio_set_sm_reg (epio_t *epio, uint8_t block, uint8_t sm, epio_sm_reg_t *reg)
	Set the SM configuration registers for a state machine.
EPIO_EXPORT void	epio_get_sm_reg (epio_t *epio, uint8_t block, uint8_t sm, epio_sm_reg_t *reg)
	Read the current SM configuration registers for a state machine.
EPIO_EXPORT void	epio_enable_sm (epio_t *epio, uint8_t block, uint8_t sm)
	Enable a state machine for execution.
EPIO_EXPORT uint8_t	epio_is_sm_enabled (epio_t *epio, uint8_t block, uint8_t sm)
	Check if a state machine is enabled.
EPIO_EXPORT void	epio_disable_sm (epio_t *epio, uint8_t block, uint8_t sm)
	Disable a state machine.

Detailed Description

Functions for creating, configuring, and destroying an epio instance.

Function Documentation

epio_disable_sm()

EPIO_EXPORT void epio_disable_sm	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm
	)

Disable a state machine.

Marks the specified SM as disabled. Disabled SMs are not advanced by epio_step_cycles() and do not execute instructions until re-enabled.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK- 1).

epio_enable_sm()

EPIO_EXPORT void epio_enable_sm	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm
	)

Enable a state machine for execution.

Marks the specified SM as enabled. Only enabled SMs are advanced by epio_step_cycles(). The SM must be fully configured before enabling.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK-1).

epio_free()

EPIO_EXPORT void epio_free

(

epio_t *

epio

)

Free an epio instance and all associated resources.

Parameters

epio	The epio instance to free. Must not be used after this call.

epio_get_gpiobase()

EPIO_EXPORT uint32_t epio_get_gpiobase	(	epio_t *	epio,
		uint8_t	block
	)

Get the GPIO base for a PIO block.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).

Returns

The GPIO base offset for this block.

epio_get_sm_debug()

EPIO_EXPORT void epio_get_sm_debug	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm,
		epio_sm_debug_t *	debug
	)

Gets the debug information for a specific state machine.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK-1).
debug	Pointer to a caller-allocated structure to receive the debug information for this SM.

epio_get_sm_reg()

EPIO_EXPORT void epio_get_sm_reg	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm,
		epio_sm_reg_t *	reg
	)

Read the current SM configuration registers for a state machine.

Copies the current register state of the specified SM into reg.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK-1).
reg	Pointer to a caller-allocated structure to receive the state.

See also

epio_set_sm_reg()

epio_init()

EPIO_EXPORT epio_t * epio_init

(

void

)

Create and initialise a new epio instance.

Allocates and returns a new epio instance with all state machines disabled and all GPIOs in their default state. The caller is responsible for configuring the instance before stepping.

Returns

Pointer to the new epio instance, or NULL on allocation failure.

See also

epio_free(), epio_from_apio()

epio_is_sm_enabled()

EPIO_EXPORT uint8_t epio_is_sm_enabled	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm
	)

Check if a state machine is enabled.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK- 1).

Returns

1 if the SM is enabled, 0 otherwise.

epio_set_gpiobase()

EPIO_EXPORT void epio_set_gpiobase	(	epio_t *	epio,
		uint8_t	block,
		uint32_t	gpio_base
	)

Set the GPIO base for a PIO block.

The RP2350 supports GPIOBASE values of 0 and 16 per PIO block, shifting the block's GPIO mapping accordingly. This must match the GPIOBASE configuration of the PIO block under test.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
gpio_base	GPIO base offset (0 or 16).

epio_set_sm_debug()

EPIO_EXPORT void epio_set_sm_debug	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm,
		epio_sm_debug_t *	debug
	)

Sets debug information for a specific state machine.

This is optional and used for logging and debugging purposes. It does not affect the execution of the state machine.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK-1).
debug	Pointer to the debug information to set for this SM.

epio_set_sm_reg()

EPIO_EXPORT void epio_set_sm_reg	(	epio_t *	epio,
		uint8_t	block,
		uint8_t	sm,
		epio_sm_reg_t *	reg
	)

Set the SM configuration registers for a state machine.

Copies the register state from reg into the specified SM. This configures the SM's PINCTRL, EXECCTRL, SHIFTCTRL, and CLKDIV registers to match a known hardware or intended configuration.

Parameters

epio	The epio instance.
block	PIO block index (0 to NUM_PIO_BLOCKS-1).
sm	State machine index within the block (0 to NUM_SMS_PER_BLOCK-1).
reg	Pointer to the register state to apply.

See also

epio_get_sm_reg()