Audio Codec (AK4954A)

Overview

This library provides functions to support use of the AK4954A audio codec found on the CY8CKIT-028-TFT shield.

Quick Start

1. Create an empty application.
2. Add this library to the application.
3. Add the following code to your application.
   The wave.h and wave.c files can be pulled from this example:
   https://github.com/Infineon/mtb-example-psoc6-i2s

NOTE: This example is targeted for Arduino-based boards.

#include "cyhal.h"
#include "cybsp.h"
#include "mtb_ak4954a.h"
#include "wave.h"
 
#define AUDIO_SYS_CLOCK_HZ (98000000u)   /* in Hz (ideally 98.304 MHz) */
#define MCLK_FREQ_HZ       (4083000u)    /* in Hz (ideally 4.096 MHz) */
#define MCLK_DUTY_CYCLE    (50.0f)       /* in %  */
 
cyhal_clock_t pll_clock;
cyhal_clock_t audio_clock;
cyhal_clock_t system_clock;
cyhal_pwm_t mclk_pwm;
cyhal_i2s_t i2s;
cyhal_i2c_t i2c;
 
const cyhal_i2c_cfg_t i2c_config = {
    .is_slave        = false,
    .address         = 0,
    .frequencyhal_hz = 400000
};
 
const cyhal_i2s_pins_t i2s_pins = {
    .sck  = CYBSP_D1,
    .ws   = CYBSP_D2,
    .data = CYBSP_D3,
    .mclk = NC
};
 
const cyhal_i2s_config_t i2s_config = {
    .is_tx_slave    = false,    /* TX is Master */
    .is_rx_slave    = false,    /* RX not used */
    .mclk_hz        = 0,        /* External MCLK not used */
    .channel_length = 32,       /* In bits */
    .word_length    = 16,       /* In bits */
    .sample_rate_hz = 16000     /* In Hz */
};
 
void i2s_isr_handler(void *arg, cyhal_i2s_event_t event)
{
    (void) arg;
    (void) event;
 
    /* Stop the I2S TX */
    cyhal_i2s_stop_tx(&i2s);
}
 
int main(void)
{
    cy_rslt_t rslt;
 
    rslt = cybsp_init();
    if(CY_RSLT_SUCCESS != rslt)
    {
        CY_ASSERT(0);
    }
 
    __enable_irq();
 
    /* Initialize the PLL */
    rslt = cyhal_clock_reserve(&pll_clock, &CYHAL_CLOCK_PLL[0]);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_clock_set_frequency(&pll_clock, AUDIO_SYS_CLOCK_HZ, NULL);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_clock_set_enabled(&pll_clock, true, true);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Initialize the audio subsystem clock (HFCLK1) */
    rslt = cyhal_clock_reserve(&audio_clock, &CYHAL_CLOCK_HF[1]);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_clock_set_source(&audio_clock, &pll_clock);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Drop HFCK1 frequency for power savings */
    cyhal_clock_set_divider(&audio_clock, 4);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    cyhal_clock_set_enabled(&audio_clock, true, true);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Initialize the system clock (HFCLK0) */
    rslt = cyhal_clock_reserve(&system_clock, &CYHAL_CLOCK_HF[0]);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_clock_set_source(&system_clock, &pll_clock);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Initialize the Master Clock with a PWM */
    rslt = cyhal_pwm_init(&mclk_pwm, CYBSP_D0, NULL);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_pwm_set_duty_cycle(&mclk_pwm, MCLK_DUTY_CYCLE, MCLK_FREQ_HZ);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    rslt = cyhal_pwm_start(&mclk_pwm);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Wait for the MCLK to clock the audio codec */
    cyhal_system_delay_ms(1u);
 
    /* Initialize the I2S */
    rslt = cyhal_i2s_init(&i2s, &i2s_pins, NULL, &i2s_config, &audio_clock);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
    cyhal_i2s_register_callback(&i2s, i2s_isr_handler, NULL);
    cyhal_i2s_enable_event(&i2s, CYHAL_I2S_ASYNC_TX_COMPLETE,
                                  CYHAL_ISR_PRIORITY_DEFAULT, true);
 
    /* Initialize the I2C to use with the audio codec */
    cyhal_i2c_init(&i2c, CYBSP_I2C_SDA, CYBSP_I2C_SCL, NULL);
    cyhal_i2c_configure(&i2c, &i2c_config);
 
    rslt = mtb_ak4954a_init(&i2c);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    /* Enable the AK4954A audio codec with the default volume */
    mtb_ak4954a_activate();
    mtb_ak4954a_adjust_volume(AK4954A_HP_VOLUME_DEFAULT);
 
    /* Setup complete */
 
    /* Start the I2S TX */
    cyhal_i2s_start_tx(&i2s);
 
    /* Initiate a transfer */
    rslt = cyhal_i2s_write_async(&i2s, wave_data, WAVE_SIZE);
    CY_ASSERT(rslt == CY_RSLT_SUCCESS);
 
    for(;;) { }
}

More information

• API Reference Guide
• Cypress Semiconductor, an Infineon Technologies Company
• Infineon GitHub
• ModusToolbox™
• PSoC™ 6 Code Examples using ModusToolbox™ IDE
• ModusToolbox™ Software

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