PIO state machine configuration. More...

Data Structures
struct	pio_sm_config
	PIO Configuration structure. More...

Functions
static void	sm_config_set_out_pins (pio_sm_config *c, uint out_base, uint out_count)
	Set the 'out' pins in a state machine configuration. More...

static void	sm_config_set_set_pins (pio_sm_config *c, uint set_base, uint set_count)
	Set the 'set' pins in a state machine configuration. More...

static void	sm_config_set_in_pins (pio_sm_config *c, uint in_base)
	Set the 'in' pins in a state machine configuration. More...

static void	sm_config_set_sideset_pins (pio_sm_config *c, uint sideset_base)
	Set the 'sideset' pins in a state machine configuration. More...

static void	sm_config_set_sideset (pio_sm_config *c, uint bit_count, bool optional, bool pindirs)
	Set the 'sideset' options in a state machine configuration. More...

static void	sm_config_set_clkdiv_int_frac (pio_sm_config *c, uint16_t div_int, uint8_t div_frac)
	Set the state machine clock divider (from integer and fractional parts - 16:8) in a state machine configuration. More...

static void	sm_config_set_clkdiv (pio_sm_config *c, float div)
	Set the state machine clock divider (from a floating point value) in a state machine configuration. More...

static void	sm_config_set_wrap (pio_sm_config *c, uint wrap_target, uint wrap)
	Set the wrap addresses in a state machine configuration. More...

static void	sm_config_set_jmp_pin (pio_sm_config *c, uint pin)
	Set the 'jmp' pin in a state machine configuration. More...

static void	sm_config_set_in_shift (pio_sm_config *c, bool shift_right, bool autopush, uint push_threshold)
	Setup 'in' shifting parameters in a state machine configuration. More...

static void	sm_config_set_out_shift (pio_sm_config *c, bool shift_right, bool autopull, uint pull_threshold)
	Setup 'out' shifting parameters in a state machine configuration. More...

static void	sm_config_set_fifo_join (pio_sm_config *c, enum pio_fifo_join join)
	Setup the FIFO joining in a state machine configuration. More...

static void	sm_config_set_out_special (pio_sm_config *c, bool sticky, bool has_enable_pin, uint enable_pin_index)
	Set special 'out' operations in a state machine configuration. More...

static void	sm_config_set_mov_status (pio_sm_config *c, enum pio_mov_status_type status_sel, uint status_n)
	Set source for 'mov status' in a state machine configuration. More...

static pio_sm_config	pio_get_default_sm_config (void)
	Get the default state machine configuration. More...

Detailed Description

PIO state machine configuration.

A PIO block needs to be configured, these functions provide helpers to set up configuration structures. See pio_sm_set_config

Function Documentation

◆ pio_get_default_sm_config()

static pio_sm_config pio_get_default_sm_config ( void )

inlinestatic

Get the default state machine configuration.

Setting	Default
Out Pins	32 starting at 0
Set Pins	0 starting at 0
In Pins (base)	0
Side Set Pins (base)	0
Side Set	disabled
Wrap	wrap=31, wrap_to=0
In Shift	shift_direction=right, autopush=false, push_threshold=32
Out Shift	shift_direction=right, autopull=false, pull_threshold=32
Jmp Pin	0
Out Special	sticky=false, has_enable_pin=false, enable_pin_index=0
Mov Status	status_sel=STATUS_TX_LESSTHAN, n=0

Returns: the default state machine configuration which can then be modified.

◆ sm_config_set_clkdiv()

static void sm_config_set_clkdiv	(	pio_sm_config *	c,
		float	div
	)

inlinestatic

Set the state machine clock divider (from a floating point value) in a state machine configuration.

The clock divider slows the state machine's execution by masking the system clock on some cycles, in a repeating pattern, so that the state machine does not advance. Effectively this produces a slower clock for the state machine to run from, which can be used to generate e.g. a particular UART baud rate. See the datasheet for further detail.

Parameters

c	Pointer to the configuration structure to modify
div	The fractional divisor to be set. 1 for full speed. An integer clock divisor of n will cause the state machine to run 1 cycle in every n. Note that for small n, the jitter introduced by a fractional divider (e.g. 2.5) may be unacceptable although it will depend on the use case.

◆ sm_config_set_clkdiv_int_frac()

static void sm_config_set_clkdiv_int_frac	(	pio_sm_config *	c,
		uint16_t	div_int,
		uint8_t	div_frac
	)

inlinestatic

Set the state machine clock divider (from integer and fractional parts - 16:8) in a state machine configuration.

The clock divider can slow the state machine's execution to some rate below the system clock frequency, by enabling the state machine on some cycles but not on others, in a regular pattern. This can be used to generate e.g. a given UART baud rate. See the datasheet for further detail.

Parameters

c	Pointer to the configuration structure to modify
div_int	Integer part of the divisor
div_frac	Fractional part in 1/256ths

See also: sm_config_set_clkdiv()

◆ sm_config_set_fifo_join()

static void sm_config_set_fifo_join	(	pio_sm_config *	c,
		enum pio_fifo_join	join
	)

inlinestatic

Setup the FIFO joining in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
join	Specifies the join type.

See also: enum pio_fifo_join

◆ sm_config_set_in_pins()

static void sm_config_set_in_pins	(	pio_sm_config *	c,
		uint	in_base
	)

inlinestatic

Set the 'in' pins in a state machine configuration.

Can overlap with the 'out', 'set' and 'sideset' pins

Parameters

c	Pointer to the configuration structure to modify
in_base	0-31 First pin to use as input

◆ sm_config_set_in_shift()

static void sm_config_set_in_shift	(	pio_sm_config *	c,
		bool	shift_right,
		bool	autopush,
		uint	push_threshold
	)

inlinestatic

Setup 'in' shifting parameters in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
shift_right	true to shift ISR to right, false to shift ISR to left
autopush	whether autopush is enabled
push_threshold	threshold in bits to shift in before auto/conditional re-pushing of the ISR

◆ sm_config_set_jmp_pin()

static void sm_config_set_jmp_pin	(	pio_sm_config *	c,
		uint	pin
	)

inlinestatic

Set the 'jmp' pin in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
pin	The raw GPIO pin number to use as the source for a `jmp pin` instruction

◆ sm_config_set_mov_status()

static void sm_config_set_mov_status	(	pio_sm_config *	c,
		enum pio_mov_status_type	status_sel,
		uint	status_n
	)

inlinestatic

Set source for 'mov status' in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
status_sel	the status operation selector.

See also: enum pio_mov_status_type

Parameters

status_n parameter for the mov status operation (currently a bit count)

◆ sm_config_set_out_pins()

static void sm_config_set_out_pins	(	pio_sm_config *	c,
		uint	out_base,
		uint	out_count
	)

inlinestatic

Set the 'out' pins in a state machine configuration.

Can overlap with the 'in', 'set' and 'sideset' pins

Parameters

c	Pointer to the configuration structure to modify
out_base	0-31 First pin to set as output
out_count	0-32 Number of pins to set.

◆ sm_config_set_out_shift()

static void sm_config_set_out_shift	(	pio_sm_config *	c,
		bool	shift_right,
		bool	autopull,
		uint	pull_threshold
	)

inlinestatic

Setup 'out' shifting parameters in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
shift_right	true to shift OSR to right, false to shift OSR to left
autopull	whether autopull is enabled
pull_threshold	threshold in bits to shift out before auto/conditional re-pulling of the OSR

◆ sm_config_set_out_special()

static void sm_config_set_out_special	(	pio_sm_config *	c,
		bool	sticky,
		bool	has_enable_pin,
		uint	enable_pin_index
	)

inlinestatic

Set special 'out' operations in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
sticky	to enable 'sticky' output (i.e. re-asserting most recent OUT/SET pin values on subsequent cycles)
has_enable_pin	true to enable auxiliary OUT enable pin
enable_pin_index	pin index for auxiliary OUT enable

◆ sm_config_set_set_pins()

static void sm_config_set_set_pins	(	pio_sm_config *	c,
		uint	set_base,
		uint	set_count
	)

inlinestatic

Set the 'set' pins in a state machine configuration.

Can overlap with the 'in', 'out' and 'sideset' pins

Parameters

c	Pointer to the configuration structure to modify
set_base	0-31 First pin to set as
set_count	0-5 Number of pins to set.

◆ sm_config_set_sideset()

static void sm_config_set_sideset	(	pio_sm_config *	c,
		uint	bit_count,
		bool	optional,
		bool	pindirs
	)

inlinestatic

Set the 'sideset' options in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
bit_count	Number of bits to steal from delay field in the instruction for use of side set (max 5)
optional	True if the topmost side set bit is used as a flag for whether to apply side set on that instruction
pindirs	True if the side set affects pin directions rather than values

◆ sm_config_set_sideset_pins()

static void sm_config_set_sideset_pins	(	pio_sm_config *	c,
		uint	sideset_base
	)

inlinestatic

Set the 'sideset' pins in a state machine configuration.

Can overlap with the 'in', 'out' and 'set' pins

Parameters

c	Pointer to the configuration structure to modify
sideset_base	0-31 base pin for 'side set'

◆ sm_config_set_wrap()

static void sm_config_set_wrap	(	pio_sm_config *	c,
		uint	wrap_target,
		uint	wrap
	)

inlinestatic

Set the wrap addresses in a state machine configuration.

Parameters

c	Pointer to the configuration structure to modify
wrap_target	the instruction memory address to wrap to
wrap	the instruction memory address after which to set the program counter to wrap_target if the instruction does not itself update the program_counter

Data Structures

Functions

Detailed Description

Function Documentation

◆ pio_get_default_sm_config()

◆ sm_config_set_clkdiv()

◆ sm_config_set_clkdiv_int_frac()

◆ sm_config_set_fifo_join()

◆ sm_config_set_in_pins()

◆ sm_config_set_in_shift()

◆ sm_config_set_jmp_pin()

◆ sm_config_set_mov_status()

◆ sm_config_set_out_pins()

◆ sm_config_set_out_shift()

◆ sm_config_set_out_special()

◆ sm_config_set_set_pins()

◆ sm_config_set_sideset()

◆ sm_config_set_sideset_pins()

◆ sm_config_set_wrap()