Bläddra i källkod

MQS: Play nice

keeps 352kHZ PWM, but reduces hardware-oversampling to 32x
dds
Frank Bösing 3 år sedan
förälder
incheckning
f2f51ea543
1 ändrade filer med 4 tillägg och 5 borttagningar
  1. +4
    -5
      output_mqs.cpp

+ 4
- 5
output_mqs.cpp Visa fil

@@ -196,12 +196,11 @@ void AudioOutputMQS::config_i2s(void)
//TODO: Check if frequencies are correct!

int fs = AUDIO_SAMPLE_RATE_EXACT;
int oversample = 64*8;
// PLL between 27*24 = 648MHz und 54*24=1296MHz
int n1 = 4; //SAI prescaler 4 => (n1*n2) = multiple of 4
int n2 = 1 + (24000000 * 27) / (fs * oversample * n1);
int n2 = 1 + (24000000 * 27) / (fs * 256 * n1);

double C = ((double)fs * oversample * n1 * n2) / 24000000;
double C = ((double)fs * 256 * n1 * n2) / 24000000;
int c0 = C;
int c2 = 10000;
int c1 = C * c2 - (c0 * c2);
@@ -217,7 +216,7 @@ void AudioOutputMQS::config_i2s(void)
| (IOMUXC_GPR_GPR1_SAI3_MCLK_DIR | IOMUXC_GPR_GPR1_SAI3_MCLK3_SEL(0)); //Select MCLK

IOMUXC_GPR_GPR2 = (IOMUXC_GPR_GPR2 & ~(IOMUXC_GPR_GPR2_MQS_OVERSAMPLE | IOMUXC_GPR_GPR2_MQS_CLK_DIV_MASK))
| IOMUXC_GPR_GPR2_MQS_EN | IOMUXC_GPR_GPR2_MQS_OVERSAMPLE | IOMUXC_GPR_GPR2_MQS_CLK_DIV(0);
| IOMUXC_GPR_GPR2_MQS_EN /*| IOMUXC_GPR_GPR2_MQS_OVERSAMPLE */| IOMUXC_GPR_GPR2_MQS_CLK_DIV(0);

if (I2S3_TCSR & I2S_TCSR_TE) return;

@@ -225,7 +224,7 @@ void AudioOutputMQS::config_i2s(void)
// I2S3_TCSR = (1<<25); //Reset
I2S3_TCR1 = I2S_TCR1_RFW(1);
I2S3_TCR2 = I2S_TCR2_SYNC(0) /*| I2S_TCR2_BCP*/ // sync=0; tx is async;
| (I2S_TCR2_BCD | I2S_TCR2_DIV((7)) | I2S_TCR2_MSEL(1));
| (I2S_TCR2_BCD | I2S_TCR2_DIV((3)) | I2S_TCR2_MSEL(1));
I2S3_TCR3 = I2S_TCR3_TCE;
I2S3_TCR4 = I2S_TCR4_FRSZ((2-1)) | I2S_TCR4_SYWD((16-1)) | I2S_TCR4_MF | I2S_TCR4_FSD /*| I2S_TCR4_FSE*/ /* | I2S_TCR4_FSP */;
I2S3_TCR5 = I2S_TCR5_WNW((16-1)) | I2S_TCR5_W0W((16-1)) | I2S_TCR5_FBT((16-1));

Laddar…
Avbryt
Spara