Confusion About E2PROM and MCU

Hello Ed,

upquark said:
Do I need an E2PROM if I'm using a permanently connected MCU?

You can certainly eliminate the E2PROM and have your MCU boot your -1702. In fact, this is the preferred configuration. Essentially, your microcontroller needs to perform the same block writes as SigmaStudio does when loading your hardware, as shown in the Capture Window:

The issue here is how to get this content into your MCU program. Right after you Link-Compile-Download your project, click Export System Files to generate a gaggle of files designed to assist with this task. ADI has a system of referencing these files within your MCU source code to bring in the latest compiled object code for your -1702. Yet, for the -170x chips, it may be easier to manually insert your DSP object code directly into byte blocks in your MCU code, revising them manually as needed. The only system file you need for this is TxBuffer_IC1.dat, which contains the "raw" hex bytes of DSP code. Your first attempts at I2C boot loading can be quite frustrating, since any one thing wrong prevents successful booting -- with nary a clue as to why. Once you get it right, it just works.

upquark said:
If an E2PROM is not necessary in this use case, how do I set up SigmaStudio correctly to account for this configuration? Do I just add the ADAU1702 and omit the E2PROM from the Hardware Configuration tab?

Absolutely. Your MCU in effect substitutes for the USBi in this case. Where I work, we use a set of jumpers to connect either the USBi or the MCU to the DSP. This way we can easily jump between SigmaStudio and uC control during development. I2C has been fast enough for us, as it takes longer for the MCU to calculate new filter params than for I2C to safeload them. Your results, of course, may vary.

Best results,

Bob

upquark said:
If an E2PROM is not necessary in this use case, how do I set up SigmaStudio correctly to account for this configuration? Do I just add the ADAU1702 and omit the E2PROM from the Hardware Configuration tab?

Yes, remove the EEPROM from the Hardware Configuration tab. It will not hurt or change much if you leave it there. All that will happen is that it will create an EEPROM image file. It will not affect the MCU operation.

Dave T

Hello Dave,

Thank you for helping with this. I'm wondering if we could insert the EEPROM image file as one huge block write within the uC code to simplify booting -- presently we do a block write for each of the instructions, parameters, etc. Just curious.

Best regards,

Bob

Hello Bob,

I have often thought about doing that. It would be SO much simpler than the convoluted files of headers and other routines that is produced with the system files export. The only little detail is that the first writes would have to be done first to configure the PLL. Then wait for lock and then continue. So you would not be able to do it in one large block. It would still have to be parsed but it is a simple format. The information is detailed in the datasheet in the "EEPROM Self Boot Data Format section. It details the header and then the body of writes and then the final footer with the checksum.

I think this would be easier than the convoluted header files produced with the System Files output.

By the way. I started this reply a LONG time ago. I must have gotten distracted and then my system rebooted overnight or something and I forgot about it. So I see your post just now and click to reply and I see my response that I had started! LOL. I am often running in three directions at once.

Dave T