ADAU1452 group delay / interface / fifo / usbi
Hello
I ve just ordered an ADAU1452 eval board and went into the datasheet.
congratulation for the exceptional device.
The routing is much more clear and looks easier than in the ADU144x family
but I couldnt find any information about the group delay from serial input to serial output, either going trough the dsp core, or when directly routed from one to another. Only informations about asrc delay. An information like the one provided in the ADAU1772 datasheet would be great.
also I couldnt find registers that would give the possibility to capture / read and write datas in/to Data memory, like with the "Interface" concept in the other SigmaDSP, how can we monitor a value at a given point in SigmaStudio, by an I2C/SPI transaction from the host MCU ?
the brochure introduce the idea of circular buffer. is there a possibility to assynchronously write a data coming from the serial input interface in a circular buffer in Data memory, independent of the DSP core program, and then to reuse the data form the circular buffer as an input of the DSP core program, this would be usefull for some specific decimation/oversampling program, Exactly like the ASRC which seems to have a fifo, but without its interpolation/decimation filter ?
also wondering if the EVAL kit MINIZ is provided with an USB interface, and/or if I could use the USBi from my ADAU1701 eval kit ?
finally I could not understand how we can write to ADAU or EEPROM from SigmaStudio, as the USB interface is only connected to the ADAU SPI slave... may be we ll get clarity on this in the user manual when its published ?
Thank you
fabriceo
Audio Signal Processors
adau1452
adau1772
Integrated/Special Purpose A/D Converters
SigmaDSP Audio Processors
Audio CODECs
adau1701
Show More
Hello,
To answer the easiest of your questions: The 1452MINZ includes a USBi, also the one from your 1701 kit is compatible.
Bob
Bump!
hello / question about how to read Data memory and replace "Interface" functionality and group delay remains
thx in advance
Hi fabriceo,
I'll try to answer some of your remaining questions to the best of my knowledge.
I think the total delay from the serial inputs to serial outputs is either 5 or 7 samples. I can't remember because I don't have my board with me right now. It should be 2 or 3 samples for the serial inputs, 1 sample for the DSP, and 2 or 3 samples for the serial outputs. So, the total is about 100 to 150 microseconds at a sample rate of 48 kHz. That's not exact, but hopefully it gives you a "ballpark" range. In any case, very low group delays (like with the ADAU1772) are not possible.
The data read-back is much simpler on the ADAU1452 compared to the ADAU1701. In fact, it's the same software-based readback functionality as the ADAU1761, ADAU1781 and ADAU1442! You simply need to insert a "DSP Readback" cell into your signal flow, and you will be able to read from that location. The compiler reserves a spot in memory for that data, and you can read directly from it. You can see a basic example in this thread (for the ADAU1781): https://ez.analog.com/message/7669#7669
I don't think multi-rate processing is possible. At least it doesn't look possible.
I think I know how to write to the self-boot EEPROM. Here are the steps if I remember correctly.
Connect ADAU1452 to USBi in SigmaStudio. Use SPI (default setting).
Connect EEPROM to USBi in SigmaStudio. Use SPI (default setting).
Link-Compile-Download the project.
Right click the ADAU1452, and choose Self-Boot Memory > Write Latest Compilation Through DSP. Do not choose the option with USB.
There will be a little dialog window that pops up with EEPROM device settings. I think the default settings are OK. So, click "Start" or "Go" or "OK." (I can't remember the label)
Anyway, this should download a little bootloader to the ADAU1452 that in turn goes off and programs the self-boot EEPROM. Pretty cool!
Also, I don't think there are any interface hardware registers, so unfortunately you can't save parameter changes back to the EEPROM.
Just realized that all of the information I included in my little step-by-step tutorial is actually included in the evaluation board user guide. D'oh!
Just open the user guide (http://www.analog.com/static/imported-files/user_guides/EVAL-ADAU1452MINIZ_User_Guide.pdf) and navigate to page 17 for a complete guide to writing to the EEPROM via the DSP on the EVAL-ADAU1452MINIZ board.
Please log in to reply.