Is SigmaDSP memory volatile?

bgoolsby Question

Oct 12, 2012 00:00

I am evaluating DSPs to use in a filtering project. I've read the datasheet for the ADAU1761 but don't see a clear answer to this: Are the program and coefficient RAM memories volatile or nonvolatile? That is, do you have to program them every time you power up the device, or does the last-programmed data stay in there?

Audio Signal Processors

SigmaDSP Audio Processors

adau1761

Report

SteveL Reply

Oct 12, 2012 00:00

Hi,

All the SigmaDSP internal memory (program and coefficient) is volatile, i.e. has to be reloaded at power-up.

However, in stand-alone mode (see the datasheet) you only need to provide a small, cheap I2C serial EEPROM containing the code and it will be loaded automatically at power-up. As far as the rest of the system is concerned that is almost the same as it being non-volatile - the Sigma can even write a few parameters back to the EEPROM if required.

Hope this helps,

Steve L.

Report

ADIApproved Reply

Oct 12, 2012 00:00

Hello,

SteveL's answer is correct, but there's one important thing to note. Not all SigmaDSPs have a self-boot function. SigmaDSPs without self-boot will need to be booted by a microcontroller or other host IC when they are powered up. Here is a table of self-booting and non-self-booting SigmaDSPs, grouped by family.

Self-Boot Feature Included
No Self-Boot Feature

ADAU1701, ADAU1702, ADAU1401, ADAU1401A
AD1940, AD1941

ADAU1442, ADAU1445, ADAU1446
ADAU1761, ADAU1461

ADAU1772
ADAU1781

Report

ADIApproved Reply

Oct 12, 2012 00:00

Here is an application note describing self-boot system design:

http://www.analog.com/static/imported-files/application_notes/AN-923.pdf

If you choose a device without self-boot, you can use SigmaStudio to generate most of the microcontroller code for you in order to boot the device. Here are two tutorials you can follow, one for microcontrollers with C compilers and one for microcontrollers that you might program in assembly or other low-level languages.