/* * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD * * SPDX-License-Identifier: Apache-2.0 *//* ... */#pragmaonce#include<stdint.h>#include"hal/sdm_types.h"#include"esp_err.h"#ifdef__cplusplusextern"C"{#endif/** * @brief Type of Sigma Delta channel handle *//* ... */typedefstructsdm_channel_t*sdm_channel_handle_t;/** * @brief Sigma Delta channel configuration *//* ... */typedefstruct{intgpio_num;/*!< GPIO number */sdm_clock_source_tclk_src;/*!< Clock source */uint32_tsample_rate_hz;/*!< Over sample rate in Hz, it determines the frequency of the carrier pulses */struct{uint32_tinvert_out:1;/*!< Whether to invert the output signal */uint32_tio_loop_back:1;/*!< For debug/test, the signal output from the GPIO will be fed to the input path as well */}{ ... }flags;/*!< Extra flags */}{ ... }sdm_config_t;/** * @brief Create a new Sigma Delta channel * * @param[in] config SDM configuration * @param[out] ret_chan Returned SDM channel handle * @return * - ESP_OK: Create SDM channel successfully * - ESP_ERR_INVALID_ARG: Create SDM channel failed because of invalid argument * - ESP_ERR_NO_MEM: Create SDM channel failed because out of memory * - ESP_ERR_NOT_FOUND: Create SDM channel failed because all channels are used up and no more free one * - ESP_FAIL: Create SDM channel failed because of other error *//* ... */esp_err_tsdm_new_channel(constsdm_config_t*config,sdm_channel_handle_t*ret_chan);/** * @brief Delete the Sigma Delta channel * * @param[in] chan SDM channel created by `sdm_new_channel` * @return * - ESP_OK: Delete the SDM channel successfully * - ESP_ERR_INVALID_ARG: Delete the SDM channel failed because of invalid argument * - ESP_ERR_INVALID_STATE: Delete the SDM channel failed because the channel is not in init state * - ESP_FAIL: Delete the SDM channel failed because of other error *//* ... */esp_err_tsdm_del_channel(sdm_channel_handle_tchan);/** * @brief Enable the Sigma Delta channel * * @note This function will transit the channel state from init to enable. * @note This function will acquire a PM lock, if a specific source clock (e.g. APB) is selected in the `sdm_config_t`, while `CONFIG_PM_ENABLE` is enabled. * * @param[in] chan SDM channel created by `sdm_new_channel` * @return * - ESP_OK: Enable SDM channel successfully * - ESP_ERR_INVALID_ARG: Enable SDM channel failed because of invalid argument * - ESP_ERR_INVALID_STATE: Enable SDM channel failed because the channel is already enabled * - ESP_FAIL: Enable SDM channel failed because of other error *//* ... */esp_err_tsdm_channel_enable(sdm_channel_handle_tchan);/** * @brief Disable the Sigma Delta channel * * @note This function will do the opposite work to the `sdm_channel_enable()` * * @param[in] chan SDM channel created by `sdm_new_channel` * @return * - ESP_OK: Disable SDM channel successfully * - ESP_ERR_INVALID_ARG: Disable SDM channel failed because of invalid argument * - ESP_ERR_INVALID_STATE: Disable SDM channel failed because the channel is not enabled yet * - ESP_FAIL: Disable SDM channel failed because of other error *//* ... */esp_err_tsdm_channel_disable(sdm_channel_handle_tchan);/** * @brief Set the pulse density of the PDM output signal. * * @note The raw output signal requires a low-pass filter to restore it into analog voltage,* the restored analog output voltage could be Vout = VDD_IO / 256 * density + VDD_IO / 2 * @note This function is allowed to run within ISR context * @note This function will be placed into IRAM if `CONFIG_SDM_CTRL_FUNC_IN_IRAM` is on, * so that it's allowed to be executed when Cache is disabled * * @param[in] chan SDM channel created by `sdm_new_channel` * @param[in] density Quantized pulse density of the PDM output signal, ranges from -128 to 127. * But the range of [-90, 90] can provide a better randomness. * @return * - ESP_OK: Set pulse density successfully * - ESP_ERR_INVALID_ARG: Set pulse density failed because of invalid argument * - ESP_FAIL: Set pulse density failed because of other error *//* ... */esp_err_tsdm_channel_set_pulse_density(sdm_channel_handle_tchan,int8_tdensity);/** * @brief The alias function of `sdm_channel_set_pulse_density`, it decides the pulse density of the output signal * * @note `sdm_channel_set_pulse_density` has a more appropriate name compare this * alias function, suggest to turn to `sdm_channel_set_pulse_density` instead * * @param[in] chan SDM channel created by `sdm_new_channel` * @param[in] duty Actually it's the quantized pulse density of the PDM output signal * * @return * - ESP_OK: Set duty cycle successfully * - ESP_ERR_INVALID_ARG: Set duty cycle failed because of invalid argument * - ESP_FAIL: Set duty cycle failed because of other error *//* ... */esp_err_tsdm_channel_set_duty(sdm_channel_handle_tchan,int8_tduty);#ifdef__cplusplus}{...}#endif
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