unleashed-firmware/lib/digital_signal/digital_signal.h
gornekich d92b0a82cc
NFC refactoring (#3050)
"A long time ago in a galaxy far, far away...." we started NFC subsystem refactoring.

Starring:

- @gornekich - NFC refactoring project lead, architect, senior developer
- @gsurkov - architect, senior developer
- @RebornedBrain - senior developer

Supporting roles:

- @skotopes, @DrZlo13, @hedger - general architecture advisors, code review
- @Astrrra, @doomwastaken, @Hellitron, @ImagineVagon333 - quality assurance

Special thanks:

@bettse, @pcunning, @nxv, @noproto, @AloneLiberty and everyone else who has been helping us all this time and contributing valuable knowledges, ideas and source code.
2023-10-24 12:08:09 +09:00

123 lines
3.5 KiB
C

/**
* @file digital_signal.h
* @brief Simple digital signal container for the DigitalSequence library.
*
* Each signal is represented by its start level (high or low) and one or more periods.
* The output will transition to its inverse value on each period boundary.
*
* Example: A signal with n periods and HIGH start level.
*
* ```
* ----+ +------+ +- ... -+
* t0 | t1 | t2 | t3 | | tn - 1
* +--------+ +----+ +--------
* ```
*
*/
#pragma once
#include <stdint.h>
#include <stdbool.h>
#ifdef __cplusplus
extern "C" {
#endif
// DigitalSignal uses 10 picosecond time units (1 tick = 10 ps).
// Use the macros below to convert the time from other units.
#define DIGITAL_SIGNAL_MS(x) ((x)*100000000UL)
#define DIGITAL_SIGNAL_US(x) ((x)*100000UL)
#define DIGITAL_SIGNAL_NS(x) ((x)*100UL)
#define DIGITAL_SIGNAL_PS(x) ((x) / 10UL)
typedef struct DigitalSignal DigitalSignal;
/**
* @brief Allocate a DigitalSignal instance with a defined maximum size.
*
* @param[in] max_size the maximum number of periods the instance will be able to contain.
* @returns pointer to the allocated instance.
*/
DigitalSignal* digital_signal_alloc(uint32_t max_size);
/**
* @brief Delete a previously allocated DigitalSignal instance.
*
* @param[in,out] signal pointer to the instance to be deleted.
*/
void digital_signal_free(DigitalSignal* signal);
/**
* @brief Append one period to the end of the DigitalSignal instance.
*
* @param[in,out] signal pointer to a the instance to append to.
* @param[in] ticks the period length, in 10 picosecond units.
*/
void digital_signal_add_period(DigitalSignal* signal, uint32_t ticks);
/**
* @brief Append one period to the end of the DigitalSignal instance, with the level specified.
*
* If the level is the same as the last level contained in the instance, then it is extened
* by the given ticks value. Otherwise, the behaviour is identical to digital_signal_add_period().
*
* Example 1: add tc with HIGH level
* ```
* before:
* ... ------+
* ta | tb
* +-------
* after:
* ... ------+ +-------
* ta | tb | tc
* +------+
* ```
* Example 2: add tc with LOW level
* ```
* before:
* ... ------+
* ta | tb
* +-------
* after:
* ... ------+
* ta | tb + tc
* +--------------
* ```
*
* @param[in,out] signal pointer to the instance to append to.
* @param[in] ticks the period length, in 10 picosecond units.
* @param[in] level the level to be set during the period.
*/
void digital_signal_add_period_with_level(DigitalSignal* signal, uint32_t ticks, bool level);
/**
* @brief Get the current start level contained in the DigitalSignal instance.
*
* If not explicitly set with digital_signal_set_start_level(), it defaults to false.
*
* @param[in] signal pointer to the instance to be queried.
* @returns the start level value.
*/
bool digital_signal_get_start_level(const DigitalSignal* signal);
/**
* @brief Set the start level contained in the DigitalSignal instance.
*
* @param[in,out] signal pointer to the instance to be modified.
* @param[in] level signal level to be set as the start level.
*/
void digital_signal_set_start_level(DigitalSignal* signal, bool level);
/**
* @brief Get the number of periods currently stored in a DigitalSignal instance.
*
* @param[in] signal pointer to the instance to be queried.
* @return the number of periods stored in the instance.
*/
uint32_t digital_signal_get_size(const DigitalSignal* signal);
#ifdef __cplusplus
}
#endif