Functions
fsp_err_t	R_PDM_Open (pdm_ctrl_t const p_ctrl, pdm_cfg_t const const p_cfg)

fsp_err_t	R_PDM_Start (pdm_ctrl_t const p_ctrl, void const p_buffer, size_t const buffer_size, uint32_t const number_of_data_to_callback)

fsp_err_t	R_PDM_Stop (pdm_ctrl_t *const p_ctrl)

fsp_err_t	R_PDM_SoundDetectionEnable (pdm_ctrl_t *const p_ctrl, pdm_sound_detection_setting_t sound_detection_setting)

fsp_err_t	R_PDM_SoundDetectionDisable (pdm_ctrl_t *const p_ctrl)

fsp_err_t	R_PDM_Read (pdm_ctrl_t const p_ctrl, void const p_dest, uint32_t const bytes)

fsp_err_t	R_PDM_StatusGet (pdm_ctrl_t const p_ctrl, pdm_status_t const p_status)

fsp_err_t	R_PDM_Close (pdm_ctrl_t *const p_ctrl)

fsp_err_t	R_PDM_CallbackSet (pdm_ctrl_t const p_ctrl, void(p_callback)(pdm_callback_args_t ), void const p_context, pdm_callback_args_t *const p_callback_memory)

Detailed Description

Driver for the PDM peripheral on RA MCUs. This module implements the PDM Interface.

Overview

The Pulse Density Modulation Interface (PDM-IF) has channels that are connectable with external microphone which outputs the pulse density modulated signal. PDM-IF can filter and convert 1-bit digital data streams that were pulse density modulated at a high sampling rate into 20-bit or 16-bit digital data at a lower sampling rate.

Features

Capable of filtering 1-bit digital input data and converting them into 20-bit or 16-bit digital data. The bit order is little-endian.
Sound detection can be enabled for each channel. A moving average filter can be enabled for sound detection. Sound detection can be used to wake up the MCU from software standby mode.
Each channel of IP includes programmable filters: 4th order sinc filter, high-pass filter (for suppression of DC bias), correction filter (for sinc passband distortion), and half-band decimation filter (for aliasing distortion). – IP supports programmable and flexible decimation ratios. – The sinc filter is selectable as first-, second-, third-, fourth-order.
IP supports DMA operation through APB. – Each channel has a 32 stage FIFO for receiving converted PDM data.
Configurable callback for each channel which notifies of received data based on a configurable threshold as well as sound detection and error events.

Configuration

Build Time Configurations for r_pdm

The following build time configurations are defined in fsp_cfg/r_pdm_cfg.h:

Configuration	Options	Default	Description
Parameter Checking	Default (BSP) Enabled Disabled	Default (BSP)	If selected code for parameter checking is included in the build.
DMAC Support	Enabled Disabled	Disabled	If enabled code for DMAC transfer support is included in the build.

Configurations for Audio > PDM (r_pdm)

This module can be added to the Stacks tab via New Stack > Audio > PDM (r_pdm).

Configuration	Options	Default	Description
Input
Edge	Rising Falling	Rising	Select the edge of input audio data.
PDM_CLK Frequency	Refer to the RA Configuration tool for available options.	module.driver.pdm.clock_div.clock_div_2	Select PDM_CLK Frequency (Hz).
Output
Bit Format	20 Bits mode {1 Sign bit and [18:0] bits of the buffer} 20 Bits mode {2 Sign bits and [18:1] bits of the buffer} 20 Bits mode {3 Sign bits and [18:2] bits of the buffer} 20 Bits mode {4 Sign bits and [18:3] bits of the buffer} 16 Bits mode {1 Sign bit and [18:4] bits of the buffer} 16 Bits mode {1 Sign bit and [17:3] bits of the buffer} 16 Bits mode {1 Sign bit and [16:2] bits of the buffer} 16 Bits mode {1 Sign bit and [15:1] bits of the buffer} 16 Bits mode {1 Sign bit and [14:0] bits of the buffer}	module.driver.pdm.pcm_width.pcm_width_20bits_0_18	Select the bit format of the PCM data stored into the data FIFO.
Target Sampling Frequency (Hz)	Manual Entry	32000	Select Target sampling Frequency (Hz).
Filter
Filter > Low-pass Filter
Low-pass Filter Input Shift	No shift 1-bit right shift 2-bits right shift 3-bits right shift	No shift	Select the low-pass (half-band decimation) filter input shift setting.
LPF Coefficient h0(10)	Value must be an integer between 0x0000 and 0x1FFF	0x0400	Specify the Low-Pass Filter Coefficient h0(10)
LPF Coefficient h1(0)	Value must be an integer between 0x0000 and 0x1FFF	0x1FF8	Specify the Low-Pass Filter Coefficient h1(0)
LPF Coefficient h1(1)	Value must be an integer between 0x0000 and 0x1FFF	0x000A	Specify the Low-Pass Filter Coefficient h1(1)
LPF Coefficient h1(2)	Value must be an integer between 0x0000 and 0x1FFF	0x1FF0	Specify the Low-Pass Filter Coefficient h1(2)
LPF Coefficient h1(3)	Value must be an integer between 0x0000 and 0x1FFF	0x0018	Specify the Low-Pass Filter Coefficient h1(3)
LPF Coefficient h1(4)	Value must be an integer between 0x0000 and 0x1FFF	0x1FDC	Specify the Low-Pass Filter Coefficient h1(4)
LPF Coefficient h1(5)	Value must be an integer between 0x0000 and 0x1FFF	0x0034	Specify the Low-Pass Filter Coefficient h1(5)
LPF Coefficient h1(6)	Value must be an integer between 0x0000 and 0x1FFF	0x1FB3	Specify the Low-Pass Filter Coefficient h1(6)
LPF Coefficient h1(7)	Value must be an integer between 0x0000 and 0x1FFF	0x0076	Specify the Low-Pass Filter Coefficient h1(7)
LPF Coefficient h1(8)	Value must be an integer between 0x0000 and 0x1FFF	0x1F2E	Specify the Low-Pass Filter Coefficient h1(8)
LPF Coefficient h1(9)	Value must be an integer between 0x0000 and 0x1FFF	0x0289	Specify the Low-Pass Filter Coefficient h1(9)
LPF Coefficient h1(10)	Value must be an integer between 0x0000 and 0x1FFF	0x0289	Specify the Low-Pass Filter Coefficient h1(10)
LPF Coefficient h1(11)	Value must be an integer between 0x0000 and 0x1FFF	0x1F2E	Specify the Low-Pass Filter Coefficient h1(11)
LPF Coefficient h1(12)	Value must be an integer between 0x0000 and 0x1FFF	0x0076	Specify the Low-Pass Filter Coefficient h1(12)
LPF Coefficient h1(13)	Value must be an integer between 0x0000 and 0x1FFF	0x1FB3	Specify the Low-Pass Filter Coefficient h1(13)
LPF Coefficient h1(14)	Value must be an integer between 0x0000 and 0x1FFF	0x0034	Specify the Low-Pass Filter Coefficient h1(14)
LPF Coefficient h1(15)	Value must be an integer between 0x0000 and 0x1FFF	0x1FDC	Specify the Low-Pass Filter Coefficient h1(15)
LPF Coefficient h1(16)	Value must be an integer between 0x0000 and 0x1FFF	0x0018	Specify the Low-Pass Filter Coefficient h1(16)
LPF Coefficient h1(17)	Value must be an integer between 0x0000 and 0x1FFF	0x1FF0	Specify the Low-Pass Filter Coefficient h1(17)
LPF Coefficient h1(18)	Value must be an integer between 0x0000 and 0x1FFF	0x000A	Specify the Low-Pass Filter Coefficient h1(18)
LPF Coefficient h1(19)	Value must be an integer between 0x0000 and 0x1FFF	0x1FF8	Specify the Low-Pass Filter Coefficient h1(19)
Filter > Compensation Filter
Compensation Filter Input Shift	No shift 1-bit right shift 2-bits right shift 3-bits right shift	No shift	Select the compensation filter input shift setting.
Compensation Filter Coefficient h(0)	Value must be an integer between 0x0000 and 0x1FFF	0x1FE8	Specify the Compensation Filter Coefficient h(0)
Compensation Filter Coefficient h(1)	Value must be an integer between 0x0000 and 0x1FFF	0x0039	Specify the Compensation Filter Coefficient h(1)
Compensation Filter Coefficient h(2)	Value must be an integer between 0x0000 and 0x1FFF	0x003C	Specify the Compensation Filter Coefficient h(2)
Compensation Filter Coefficient h(3)	Value must be an integer between 0x0000 and 0x1FFF	0x1E56	Specify the Compensation Filter Coefficient h(3)
Compensation Filter Coefficient h(4)	Value must be an integer between 0x0000 and 0x1FFF	0x01DC	Specify the Compensation Filter Coefficient h(4)
Compensation Filter Coefficient h(5)	Value must be an integer between 0x0000 and 0x1FFF	0x06E1	Specify the Compensation Filter Coefficient h(5)
Compensation Filter Coefficient h(6)	Value must be an integer between 0x0000 and 0x1FFF	0x01DC	Specify the Compensation Filter Coefficient h(6)
Compensation Filter Coefficient h(7)	Value must be an integer between 0x0000 and 0x1FFF	0x1E56	Specify the Compensation Filter Coefficient h(7)
Compensation Filter Coefficient h(8)	Value must be an integer between 0x0000 and 0x1FFF	0x003C	Specify the Compensation Filter Coefficient h(8)
Compensation Filter Coefficient h(9)	Value must be an integer between 0x0000 and 0x1FFF	0x0039	Specify the Compensation Filter Coefficient h(9)
Compensation Filter Coefficient h(10)	Value must be an integer between 0x0000 and 0x1FFF	0x1FE8	Specify the Compensation Filter Coefficient h(10)
Filter > High-pass Filter
High-pass Filter Input Shift	No shift 1-bit right shift 2-bits right shift 3-bits right shift	No shift	Select the high-pass filter input shift setting.
HPF Coefficient s(0)	Value must be an integer between 0x0000 and 0xFFFF	0x3F61	Specify the High-Pass Filter Coefficient s(0)
HPF Coefficient k(1)	Value must be an integer between 0x0000 and 0xFFFF	0x3EC1	Specify the High-Pass Filter Coefficient k(1)
HPF Coefficient h(0)	Value must be an integer between 0x0000 and 0xFFFF	0x4000	Specify the High-Pass Filter Coefficient h(0)
HPF Coefficient h(1)	Value must be an integer between 0x0000 and 0xFFFF	0xC000	Specify the High-Pass Filter Coefficient h(1)
Moving Average Mode	1-order (filter is skipped) 2-order 4-order	1-order (filter is skipped)	Select the moving average mode for sound detection data.
Sinc Filter Mode	1-order 2-order 3-order 4-order	4-order	Select the sinc filter mode setting.
Data Reception
Buffer Overwrite Detection Enable	Enabled Disabled	Enabled	Select buffer overwrite detection.
Data Reception Interrupt Threshold	1 or more data 2 or more data 4 or more data 8 or more data 16 or more data	16 or more data	Select Data reception interrupt threshold.
Short Circuit Detection
Short Circuit Detection Enable	Enabled Disabled	Disabled	Select short circuit detection.
Short Circuit Detection High Continuous Detection Count	Value must be an integer between 0x0000 and 0x1FFF	0x0	Specify the Short circuit detection High Continuous detection count.
Short Circuit Detection Low Continuous Detection Count	Value must be an integer between 0x0000 and 0x1FFF	0x0	Short circuit detection Low Continuous detection count.
Overvoltage Detection
Overvoltage Detection Lower Limit Enable	Enabled Disabled	Disabled	Select overvoltage detection lower limit.
Overvoltage Detection Lower Limit	Value must be an integer between 0x0000 and 0xFFFFF	0x0	Specify the Overvoltage detection lower limit
Overvoltage Detection Upper Limit Enable	Enabled Disabled	Disabled	Select overvoltage detection upper limit.
Overvoltage Detection Upper Limit	Value must be an integer between 0x0000 and 0xFFFFF	0x0	Specify the Overvoltage detection upper limit
Interrupt
Callback	Name must be a valid C symbol	NULL	A user callback function can be provided. If this callback function is provided, it will be called from all three interrupt service routines (ISR).
Sound Detection Interrupt Priority	MCU Specific Options		Select the sound detection interrupt priority.
Data Reception Interrupt Priority	MCU Specific Options		Select the data reception interrupt priority.
Error Detection Interrupt Priority	MCU Specific Options		Select the error detection interrupt priority.
Name	Name must be a valid C symbol	g_pdm0	Module name.
Channel	Value must be an non-negative integer	0	Specify the PDM channel.

Usage Notes

Startup and Settling Time

Upon calling R_PDM_Open the user must wait for the filters to settle and any connected microphones to startup, otherwise PDM data may not be correct upon calling R_PDM_Start.

A macro G_PDMn_FILTER_SETTLING_TIME_US (where n is the channel number) is generated for the settling time. The user can use this macro to delay for the settling time via their preferred method of doing a delay.

In addition to the filter settling time any connected microphone startup time should be accounted for. This can be found in the connected microphone's datasheet.

Audio Data

PDM hardware converts PDM data to PCM data.

Data arrays have the following size, alignment, and length based on the "Bit Depth" setting:

Bit Depth	Array Data Type	Required Alignment
16 Bits	32-bit integer, right justified	4 byte alignment
20 Bits	32-bit integer, right justified	4 byte alignment

Data Format for 16 Bits

Bit	Description
31-20	Fixed to 0
19-16	Sign bits
15-0	Fixed-point data

Data Format for 20 Bits

Bit	Description
31-20	Fixed to 0
19-0	Fixed-point data

Modes of Operation

In addition to calling R_PDM_Open, other APIs need to be called to activate certain features of PDM. The following table lists what each API controls:

API	Features Enabled by API
R_PDM_Open	over/undervoltage detection, short circuit detection
R_PDM_Start	data reception via interrupts or DMAC depending configuration, error interrupts
R_PDM_SoundDetectionEnable	sound detection, sound detection thresholds, error interrupts

Error Interrupts

Error interrupts are only enabled when data reception is enabled (R_PDM_Start has been called) OR sound detection is enabled (R_PDM_SoundDetectionEnable has been called).

R_PDM_StatusGet can be called to get error statuses if error interrupts are not enabled (e.g. if only R_PDM_Open has been called).

Low Power Mode

Note: In order to use PDM during low power mode MOCO must be enabled for software standby mode (see MOCOSCR register).

Some microphones support going into a low power mode by changing the PDM clock to a low frequency. In order to do this with r_pdm the module instance should be closed and reopened with a separate configuration that uses a lower PDM clock.

Limitations

Stereo mode is not fully supported. Two r_pdm driver instances can be used in combination with the pcm_edge configuration to get left/right stereo output from an appropriately configured PDM data stream, however, the data from these two instances will not be synchronized. Full synchronization of PDM channels requires using PDM mirror registers and starting data reading at the same time between channels. In the future a stereo-specific driver may be implemented using the r_pdm driver as a lower level driver to cover this use case.
When calling R_PDM_Start any data in the FIFO before DATRE is enabled will be discarded.

Examples

Basic Example

#define PDM_BUFFER_NUM_SAMPLES      1024                       // Number of samples to store in data buffer
#define PDM_CALLBACK_NUM_SAMPLES    PDM_BUFFER_NUM_SAMPLES / 2 // Number of samples to store in data buffer before getting a callback
#define PDM_MIC_STARTUP_TIME_US     35000                      // PDM microphone startup time, RA8P1_EK mic startup time is 35ms
#define PDM_SDE_UPPER_LIMIT         5000                       // Detect sound above this value
#define PDM_SDE_LOWER_LIMIT         0xFFF80000                 // Detect sound below this value
uint32_t g_pdm0_buffer[PDM_BUFFER_NUM_SAMPLES];
void r_pdm_basic_messaging_core0_example (void)
{
    /* Open PDM instance. */
    fsp_err_t err = R_PDM_Open(&g_pdm0_ctrl, &g_pdm0_cfg);
    assert(FSP_SUCCESS == err);
    /* Wait for PDM filters to settle. Use settling time calculated by e2 studio.
     * Also wait for PDM mic to startup. */
    R_BSP_SoftwareDelay(G_PDM0_FILTER_SETTLING_TIME_US + PDM_MIC_STARTUP_TIME_US, BSP_DELAY_UNITS_MICROSECONDS);
    /* Enable sound detection (if desired). */
    pdm_sound_detection_setting_t sound_detection_setting =
    {
        .sound_detection_lower_limit = PDM_SDE_LOWER_LIMIT,
        .sound_detection_upper_limit = PDM_SDE_UPPER_LIMIT
    };
    fsp_err_t err = R_PDM_SoundDetectionEnable(&g_pdm0_ctrl, sound_detection_setting);
    assert(FSP_SUCCESS == err);
    /* Start receiving PDM data. */
    err = R_PDM_Start(&g_pdm0_ctrl, g_pdm0_buffer, sizeof(g_pdm0_buffer), PDM_CALLBACK_NUM_SAMPLES);
    assert(FSP_SUCCESS == err);
    /* DATA PROCESSING HERE */
    /* Stop receiving PDM data. */
    err = R_PDM_Stop(&g_pdm0_ctrl);
    assert(FSP_SUCCESS == err);
    /* Close PDM instance. */
    err = R_PDM_Close(&g_pdm0_ctrl);
    assert(FSP_SUCCESS == err);
}
void pdm_example_callback (pdm_callback_args_t * p_args)
{
    switch (p_args->event)
    {
        case PDM_EVENT_SOUND_DETECTION:
        {
            /* Sound has been detected based on configured thresholds. */
            break;
        }
        case PDM_EVENT_DATA:
        {
            /* PDM_CALLBACK_NUM_SAMPLES has been stored in g_pdm0_buffer. */
            break;
        }
        case PDM_EVENT_ERROR:
        {
            if (p_args->error & PDM_ERROR_SHORT_CIRCUIT)
            {
                /* Short circuit has been detected based on configured counts */
            }
            if (p_args->error & PDM_ERROR_OVERVOLTAGE_LOWER)
            {
                /* Overvoltage has been detected based on configured lower limit */
            }
            if (p_args->error & PDM_ERROR_OVERVOLTAGE_UPPER)
            {
                /* Overvoltage has been detected based on configured upper limit */
            }
            if (p_args->error & PDM_ERROR_BUFFER_OVERWRITE)
            {
                /* Buffer overwrite has occurred */
            }
            break;
        }
        default:
        {
            break;
        }
    }
}

Data Structures
struct	pdm_instance_ctrl_t

struct	pdm_extended_cfg_t

Macros
#define	PDM_NUM_HPF_COEFFICIENT_H
	Number of high pass filter h coefficients.

#define	PDM_NUM_COMPENSATION_FILTER_COEFFICIENT_H
	Number of compensation filter h coefficients.

#define	PDM_NUM_LPF_FILTER_COEFFICIENT_H1
	Number of low pass filter h1 coefficients.

Enumerations
enum	pdm_clk_div_t

enum	pdm_moving_average_mode_t

enum	pdm_low_pass_filter_shift_t

enum	pdm_compensation_filter_shift_t

enum	pdm_high_pass_filter_shift_t

enum	pdm_sinc_filter_mode_t

enum	pdm_interrupt_threshold_t

enum	pdm_short_circuit_enable_t

enum	pdm_overvoltage_lower_limit_enable_t

enum	pdm_overvoltage_upper_limit_enable_t

enum	pdm_buffer_overwrite_detection_enable_t

Data Structure Documentation

◆ pdm_instance_ctrl_t

struct pdm_instance_ctrl_t

Channel instance control block. DO NOT INITIALIZE. Initialization occurs when pdm_api_t::open is called.

◆ pdm_extended_cfg_t

struct pdm_extended_cfg_t

PDM configuration extension. This extension is optional.

Data Fields
pdm_clk_div_t	clock_div	PDM_CLKn's division ratio to core clock.
pdm_short_circuit_enable_t	short_circuit_detection_enable	Short circuit detection enable. Function Settings.
pdm_overvoltage_lower_limit_enable_t	over_voltage_lower_limit_detection_enable	Overvoltage detection lower limit enable.
pdm_overvoltage_upper_limit_enable_t	over_voltage_upper_limit_detection_enable	Overvoltage detection upper limit enable.
pdm_buffer_overwrite_detection_enable_t	buffer_overwrite_detection_enable	Buffer overwrite detection enable.
pdm_moving_average_mode_t	moving_average_mode	Moving average mode f or sound detection data. Filter Settings.
pdm_low_pass_filter_shift_t	low_pass_filter_shift	Low-pass (half -band decimation) filter input shift setting.
pdm_compensation_filter_shift_t	compensation_filter_shift	Compensation filter input shift setting.
pdm_high_pass_filter_shift_t	high_pass_filter_shift	High-pass filter input shift setting.
pdm_sinc_filter_mode_t	sinc_filter_mode	Sinc filter mode setting.
uint8_t	sincrng	Sinc filter output valid range.
uint8_t	sincdec	Sinc filter decimation ratio.
uint16_t	hpf_coefficient_s0	High-pass filter coefficient s0 (16-bit signed fixed point data)
uint16_t	hpf_coefficient_k1	High-pass filter coefficient k1 (16-bit signed fixed point data)
uint16_t	hpf_coefficient_h[PDM_NUM_HPF_COEFFICIENT_H]	High-pass filter coefficient h(p) (16-bit signed fixed point data)
uint16_t	compensation_filter_coefficient_h[PDM_NUM_COMPENSATION_FILTER_COEFFICIENT_H]	High-pass filter coefficient h(p) (13-bit signed fixed point data)
uint16_t	lpf_coefficient_h0	Low-pass (half-band decimation) filter coefficient h0 (13-bit signed fixed point data)
uint16_t	lpf_coefficient_h1[PDM_NUM_LPF_FILTER_COEFFICIENT_H1]	Low-pass (half-band decimation) filter coefficient h1 (13-bit signed fixed point data)
pdm_interrupt_threshold_t	interrupt_threshold	Data reception interrupt threshold. Data Reception.
uint16_t	short_circuit_count_h	Short circuit detection High Continuous detection count. Short-Circuit Detection.
uint16_t	short_circuit_count_l	Continuous detection count.
uint32_t	overvoltage_detection_lower_limit	Overvoltage detection lower limit (20-bit signed fixed point data) Overvoltage Detection.
uint32_t	overvoltage_detection_upper_limit	Overvoltage detection upper limit (20-bit signed fixed point data)

Enumeration Type Documentation

◆ pdm_clk_div_t

enum pdm_clk_div_t

PDM_CLKn's division ratio to core clock.

Enumerator
PDM_CLOCK_DIV_2	0000b: 1/2
PDM_CLOCK_DIV_4	0001b: 1/4
PDM_CLOCK_DIV_6	0010b: 1/6
PDM_CLOCK_DIV_8	0011b: 1/8
PDM_CLOCK_DIV_10	0100b: 1/10
PDM_CLOCK_DIV_12	0101b: 1/12
PDM_CLOCK_DIV_14	0110b: 1/14
PDM_CLOCK_DIV_16	0111b: 1/16
PDM_CLOCK_DIV_18	1000b: 1/18
PDM_CLOCK_DIV_20	1001b: 1/20
PDM_CLOCK_DIV_22	1010b: 1/22
PDM_CLOCK_DIV_24	1011b: 1/24
PDM_CLOCK_DIV_26	1100b: 1/26
PDM_CLOCK_DIV_28	1101b: 1/28
PDM_CLOCK_DIV_30	1110b: 1/30
PDM_CLOCK_DIV_32	1111b: 1/32

◆ pdm_moving_average_mode_t

enum pdm_moving_average_mode_t

Moving average mode for sound detection data.

Enumerator
PDM_MOVING_AVERAGE_MODE_1_ORDER	1-order
PDM_MOVING_AVERAGE_MODE_2_ORDER	2-order
PDM_MOVING_AVERAGE_MODE_4_ORDER	4-order

◆ pdm_low_pass_filter_shift_t

enum pdm_low_pass_filter_shift_t

Low-pass (half-band decimation) filter input shift setting.

Enumerator
PDM_LPF_RIGHT_SHIFT_0	No shift.
PDM_LPF_RIGHT_SHIFT_1	1-bit right shift
PDM_LPF_RIGHT_SHIFT_2	2-bit right shift
PDM_LPF_RIGHT_SHIFT_3	3-bit right shift

◆ pdm_compensation_filter_shift_t

enum pdm_compensation_filter_shift_t

Compensation filter input shift setting.

Enumerator
PDM_COMPENSATION_FILTER_RIGHT_SHIFT_0	No shift.
PDM_COMPENSATION_FILTER_RIGHT_SHIFT_1	1-bit right shift
PDM_COMPENSATION_FILTER_RIGHT_SHIFT_2	2-bit right shift
PDM_COMPENSATION_FILTER_RIGHT_SHIFT_3	3-bit right shift

◆ pdm_high_pass_filter_shift_t

enum pdm_high_pass_filter_shift_t

High-pass filter input shift setting.

Enumerator
PDM_HPF_RIGHT_SHIFT_0	No shift.
PDM_HPF_RIGHT_SHIFT_1	1-bit right shift
PDM_HPF_RIGHT_SHIFT_2	2-bit right shift
PDM_HPF_RIGHT_SHIFT_3	3-bit right shift

◆ pdm_sinc_filter_mode_t

enum pdm_sinc_filter_mode_t

Sinc filter mode setting.

Enumerator
PDM_SINC_FILTER_MODE_1	1-order
PDM_SINC_FILTER_MODE_2	2-order
PDM_SINC_FILTER_MODE_3	3-order
PDM_SINC_FILTER_MODE_4	4-order

◆ pdm_interrupt_threshold_t

enum pdm_interrupt_threshold_t

Data reception interrupt threshold.

Enumerator
PDM_INTERRUPT_THRESHOLD_1	000b: Output interrupt when receiving 1 or more data
PDM_INTERRUPT_THRESHOLD_2	001b: Output interrupt when receiving 2 or more data
PDM_INTERRUPT_THRESHOLD_4	010b: Output interrupt when receiving 4 or more data
PDM_INTERRUPT_THRESHOLD_8	011b: Output interrupt when receiving 8 or more data
PDM_INTERRUPT_THRESHOLD_16	100b: Output interrupt when receiving 16 or more data

◆ pdm_short_circuit_enable_t

enum pdm_short_circuit_enable_t

Short circuit detection enable setting.

Enumerator
PDM_SHORT_CIRCUIT_DISABLED	Short circuit disabled.
PDM_SHORT_CIRCUIT_ENABLED	Short circuit enabled.

◆ pdm_overvoltage_lower_limit_enable_t

enum pdm_overvoltage_lower_limit_enable_t

Overvoltage lower limit enable setting.

Enumerator
PDM_OVERVOLTAGE_LOWER_LIMIT_DISABLED	Overvoltage lower limit disabled.
PDM_OVERVOLTAGE_LOWER_LIMIT_ENABLED	Overvoltage lower limit enabled.

◆ pdm_overvoltage_upper_limit_enable_t

enum pdm_overvoltage_upper_limit_enable_t

Overvoltage upper limit enable setting.

Enumerator
PDM_OVERVOLTAGE_UPPER_LIMIT_DISABLED	Overvoltage upper limit disabled.
PDM_OVERVOLTAGE_UPPER_LIMIT_ENABLED	Overvoltage upper limit enabled.

◆ pdm_buffer_overwrite_detection_enable_t

enum pdm_buffer_overwrite_detection_enable_t

Buffer overwrite detection enable setting.

Enumerator
PDM_BUFFER_OVERWRITE_DETECTION_DISABLED	Buffer overwrite detection disabled.
PDM_BUFFER_OVERWRITE_DETECTION_ENABLED	Buffer overwrite detection enabled.

Function Documentation

◆ R_PDM_Open()

fsp_err_t R_PDM_Open	(	pdm_ctrl_t *const	p_ctrl,
		pdm_cfg_t const *const	p_cfg
	)

Opens the PDM. Implements pdm_api_t::open.

This function sets this clock divisor and the configurations specified in pdm_cfg_t.

Return values

FSP_SUCCESS	Ready for PDM communication.
FSP_ERR_ASSERTION	The pointer to p_ctrl or p_cfg is null.
FSP_ERR_ALREADY_OPEN	The control block has already been opened.
FSP_ERR_IP_CHANNEL_NOT_PRESENT	Channel number is not available on this device.

Returns: See Common Error Codes or functions called by this function for other possible return codes.

◆ R_PDM_Start()

fsp_err_t R_PDM_Start	(	pdm_ctrl_t *const	p_ctrl,
		void *const	p_buffer,
		size_t const	buffer_size,
		uint32_t const	number_of_data_to_callback
	)

Starts PDM. Implements pdm_api_t::start.

This function enables reception, and enables any transfer instances used.

The PDM will start on the next frame boundary.

Return values

FSP_SUCCESS	PDM communication stop request issued.
FSP_ERR_ASSERTION	The pointer to p_ctrl was null.
FSP_ERR_INVALID_SIZE	The size of buffer is not a multiple of pdm_interrupt_threshold_t.
FSP_ERR_INVALID_ALIGNMENT	The alignment of argument buffer_size is not matched with hardware specification.
FSP_ERR_NOT_OPEN	The channel is not opened.

Returns: See Common Error Codes or lower level drivers for other possible return codes.

◆ R_PDM_Stop()

fsp_err_t R_PDM_Stop ( pdm_ctrl_t *const p_ctrl )

Stops PDM. Implements pdm_api_t::stop.

This function disables reception, and disables any transfer instances used.

The PDM will stop on the next frame boundary.

Return values

FSP_SUCCESS	PDM communication stop request issued.
FSP_ERR_ASSERTION	The pointer to p_ctrl was null.
FSP_ERR_NOT_OPEN	The channel is not opened.

Returns: See Common Error Codes or lower level drivers for other possible return codes.

◆ R_PDM_SoundDetectionEnable()

fsp_err_t R_PDM_SoundDetectionEnable	(	pdm_ctrl_t *const	p_ctrl,
		pdm_sound_detection_setting_t	sound_detection_setting
	)

Configures and enables sound detection. Implements pdm_api_t::soundDetectionEnable.

This function configures sound detection based on the passed in settings. It then enables sound detection.

Return values

FSP_SUCCESS	Sound detection configured and enabled.
FSP_ERR_ASSERTION	The pointer to p_ctrl was null.
FSP_ERR_NOT_OPEN	The channel is not opened.

Returns: See Common Error Codes or lower level drivers for other possible return codes.

◆ R_PDM_SoundDetectionDisable()

fsp_err_t R_PDM_SoundDetectionDisable ( pdm_ctrl_t *const p_ctrl )

Disables sound detection. Implements pdm_api_t::soundDetectionDisable.

This function disables sound detection.

Return values

FSP_SUCCESS	Sound detection disabled.
FSP_ERR_ASSERTION	The pointer to p_ctrl was null.
FSP_ERR_NOT_OPEN	The channel is not opened.

Returns: See Common Error Codes or lower level drivers for other possible return codes.

◆ R_PDM_Read()

fsp_err_t R_PDM_Read	(	pdm_ctrl_t *const	p_ctrl,
		void *const	p_dest,
		uint32_t const	bytes
	)

This function is not supported. Implements pdm_api_t::read.

Return values

FSP_ERR_UNSUPPORTED This function is not supported.

◆ R_PDM_StatusGet()

fsp_err_t R_PDM_StatusGet	(	pdm_ctrl_t *const	p_ctrl,
		pdm_status_t *const	p_status
	)

Gets PDM status and stores it in provided pointer p_status. Implements pdm_api_t::statusGet.

Calling this function will clear any set error flags in the hardware.

Return values

FSP_SUCCESS	Information stored successfully.
FSP_ERR_ASSERTION	The p_ctrl or p_status parameter was null.
FSP_ERR_NOT_OPEN	The channel is not opened.

◆ R_PDM_Close()

fsp_err_t R_PDM_Close ( pdm_ctrl_t *const p_ctrl )

Closes PDM. Implements pdm_api_t::close.

This function powers down the PDM and closes the lower level timer and transfer drivers if they are used.

Return values

FSP_SUCCESS	Device closed successfully.
FSP_ERR_ASSERTION	The pointer to p_ctrl was null.
FSP_ERR_NOT_OPEN	The channel is not opened.

◆ R_PDM_CallbackSet()

fsp_err_t R_PDM_CallbackSet	(	pdm_ctrl_t *const	p_ctrl,
		void()(pdm_callback_args_t )	p_callback,
		void *const	p_context,
		pdm_callback_args_t *const	p_callback_memory
	)

Updates the user callback and has option of providing memory for callback structure. Implements pdm_api_t::callbackSet

Return values

FSP_SUCCESS	Callback updated successfully.
FSP_ERR_ASSERTION	A required pointer is NULL.
FSP_ERR_NOT_OPEN	The control block has not been opened.
FSP_ERR_NO_CALLBACK_MEMORY	p_callback is non-secure and p_callback_memory is either secure or NULL.

Functions

Detailed Description

Overview

Features

Configuration

Build Time Configurations for r_pdm

Configurations for Audio > PDM (r_pdm)

Usage Notes

Startup and Settling Time

Audio Data

Data Format for 16 Bits

Data Format for 20 Bits

Modes of Operation

Error Interrupts

Low Power Mode

Limitations

Examples

Basic Example

Data Structures

Macros

Enumerations

Data Structure Documentation

◆ pdm_instance_ctrl_t

◆ pdm_extended_cfg_t

Enumeration Type Documentation

◆ pdm_clk_div_t

◆ pdm_moving_average_mode_t

◆ pdm_low_pass_filter_shift_t

◆ pdm_compensation_filter_shift_t

◆ pdm_high_pass_filter_shift_t

◆ pdm_sinc_filter_mode_t

◆ pdm_interrupt_threshold_t

◆ pdm_short_circuit_enable_t

◆ pdm_overvoltage_lower_limit_enable_t

◆ pdm_overvoltage_upper_limit_enable_t

◆ pdm_buffer_overwrite_detection_enable_t

Function Documentation

◆ R_PDM_Open()

◆ R_PDM_Start()

◆ R_PDM_Stop()

◆ R_PDM_SoundDetectionEnable()

◆ R_PDM_SoundDetectionDisable()

◆ R_PDM_Read()

◆ R_PDM_StatusGet()

◆ R_PDM_Close()

◆ R_PDM_CallbackSet()