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External SPI delay for long delays

Category: Datasheet/Specs
Product Number: ADAU1452
Software Version: SigmaStudio 4.7


I have a PCBA with an ADAU1401 performing some ADC-DSP-DAC tasks and it works pretty fine. now I need to add a big delay to the audio, so I came to the possible solution of codec+DSP.

I am trying to set up a big delay (up to 34 seconds) to a pair of audio outputs. I have thought of the ADAU1452 (ADAU145x and ADAU146x series) to perform this task, due to the External SPI Delay feature. My audio signal has a data rate of 48 kSa/s. I have done some calculations and I would need 24.4 Mib (3.05MiB) of memory per channel for this purpose. Up to here, it seems fine, it would be a couple of 4MB memories (or a single memory of 8MB, if this is possible).

Now, the tricky part: I just find NOR flash memories in this range of memories and simple SPI interface. I am concerned of the duration of the memory, as it will be cycling all the memory around twice a minute (in the best case, which would be the DSP writting to the memory in full pages). This gives us (for a "Min. 100K Program-Erase cycles per sector" memory) around 50k minutes of working time, which is around 34 days of continuous delayed audio played. I am planning to use these equipments in installations that should be installed for years and years.

So, my question here is: is there any other kind of memories (that I am not aware of) or any other way around that can make this project to trully work?

Many thanks in advance.

Best regards,


Parents Reply
  • Thanks Joe, that is what I thought. At the moment (at least at big component sourcers such as Mouser, Digikey and so on) I can only find the IS66WVS4M8BLL chip suitable for this purpose, if you (or anyone in the forum) could help me find any other alternative, so my design does not depends exclusively on this memory, I would really appreciate it