Using 1600 ms digital audio delay pool on ADAU1463

Hello HowardF,

HowardF said:
The delay module in Basic DSP -> DSP Functions -> Delay -> Delay only allows the use of DM0, DM1 or PM.

If you choose the basic delay block from library, then it uses the internal memory (DM0, DM1, PM) for delay line. There are options for external SPI delay etc.

In the below project, I created a 1.6ms delay in the audio path using internal memory. You can see both DM0 and DM1 are at 94% use.

So, it's possible to create a 1.6ms delay but you have to have memory for other processing algorithms like FIR etc as well. So, it's not possible to use all the DM, PM only for delay in a big project which has so many algorithms, so you can use external mem for larger delay and use the available internal mem after your design.

If you only want only a 1.6ms delay with input and output, then it's possible. So, it all depends on your application,

Regards,

Harish

Hi,

Despite the datasheeting saying the ADAU1463 has "upto" 80 kWords of DM, it only has 48 kWords, which equates to a maximum of 1,000 ms of delay

The datasheet implies that there is 1600 ms of delay memory in addition to the DM and PM. Is that not the case?

Hello HowardF,

My apologies, I thought you were using ADAU1467 which has more memory.

For ADAU1463, the data memory (DM) is 48K only, not 80K which is for 1467, and the PM is 16k for 1463.

The datasheet is common for both parts (1463/1467) for almost everything and the main distinction between these two parts is the memory which is tabled separately for both parts in the datasheet.

So, 1600ms is meant for ADAU1467, it's achievable there.

For ADAU1463, we can achieve 1300ms with a basic input and output program.

If I add any heavy algorithm or increase the delay any further, I will get a compilation error.

Regards,

Harish