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esp-idf/components/esp_driver_twai/include/esp_private/twai_utils.h
2025-04-07 21:49:18 +08:00

47 lines
1.6 KiB
C

/*
* SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Apache-2.0
*/
#pragma once
#include "esp_twai_types.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief TWAI hardware-dependent bit-timing constant
*
* Used for calculating and checking bit-timing parameters
*/
typedef struct {
uint32_t brp_min; /* Bit-rate prescaler */
uint32_t brp_max;
uint8_t tseg1_min; /* Time segment 1 = prop_seg + phase_seg1 */
uint8_t tseg1_max;
uint8_t tseg2_min; /* Time segment 2 = phase_seg2 */
uint8_t tseg2_max;
uint8_t sjw_max; /* Synchronisation jump width */
} twai_timing_constraint_t;
/**
* @brief Calculate TWAI timing parameters for a given source frequency and baud rate.
*
* This function computes the bit timing parameters (`brp`, `prop_seg`, `tseg_1`, `tseg_2`, `sjw`)
* based on the provided source clock frequency and desired baud rate. It also adjusts for the sample
* point ratio if specified.
*
* @param source_freq The source clock frequency in Hz.
* @param in_param Pointer to the input configuration, which includes baud rate and sample rate.
* @param hw_limit Pointer to const of hardware register limitation.
* @param out_param Pointer to the output structure where the calculated timing parameters will be stored.
* @return the actual hardware adopted baudrate.
*/
uint32_t twai_node_timing_calc_param(const uint32_t source_freq, const twai_timing_basic_config_t *in_param, const twai_timing_constraint_t *hw_limit, twai_timing_advanced_config_t *out_param);
#ifdef __cplusplus
}
#endif