Posted on July 30, 2017 at 23:42 Nice one
!
I tried adding a delay line and using float buffers in sdram, but the data loaded from sdram appears to be corrupted.
Mapping:
#define DELAY_BUFFER_SIZE ((uint32_t)(DEFAULT_AUDIO_IN_FREQ))// 1 second#define AUDIO_BUFFER_IN AUDIO_REC_START_ADDR#define AUDIO_BUFFER_OUT (AUDIO_BUFFER_IN + (AUDIO_BLOCK_SIZE*2))#define DELAY_BUFFER_START (AUDIO_BUFFER_OUT + (AUDIO_BLOCK_SIZE*2))�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?�?
Example:
void Delay(){ uint32_t i, j; arm_q15_to_float ((uint16_t*)(DELAY_BUFFER_START + dReadPos), delayBufferRead, AUDIO_BLOCK_SIZE); for(i=0, j=0; i < AUDIO_BLOCK_SIZE; i+=2 , ++j) { dSample = delayBufferRead[j] * dFeedback; delayBufferWrite[j] = float_buffer_in[i] + dSample; float_buffer_out[i] = float_buffer_in[i] + dSample * dMix; float_buffer_out[i+1] = float_buffer_out[i]; dWritePos = (dWritePos + 1) % DELAY_BUFFER_SIZE; dReadPos = (dReadPos + 1) % DELAY_BUFFER_SIZE; } arm_float_to_q15 (delayBufferWrite, (uint16_t*)(DELAY_BUFFER_START + dWritePos), AUDIO_BLOCK_SIZE);}�?�?�?�?�?�?�?�?�?�?�?�?�?�?
The dry data, saved in the buffers starting fromaddress0x2002f864 (SRAM),is clear.
float32_t float_buffer_in[AUDIO_BLOCK_SIZE];�?�?float32_t float_buffer_out[AUDIO_BLOCK_SIZE];�?�?�?�?
Only the data from the delay line in SDRAM is corrupted
