I read the full documentation of 8631 and also the application note for C6711 (which should be good also for 6418), where MCBSp is configured to receive 20 bit frames with 2 byte delay and a single 16 bit word, but I don't understand a basic thing.
How can I start ADS8361 operations getting samples starting from the first of the 4 channels? and stop operations at any time and then restart again getting samples starting from the first channel?
Hi Alberto,
This sounds like a very interesting project to use the ADS8361 with! One thing that is not made very clear in the ADS8361 data sheet is that the device starts off from power up in Mode 1. There is another application note here http://www.ti.com/lit/an/slaa167/slaa167.pdf which you might find helpful. That document was written for the F2000 series DSP's but it goes into more detail and includes a few scope shots that may help you realize a method to get your project running.
Figure 4 in the application note mentioned above shows how you can drive M0 low via GPIO and force the ADS8361 into a synchronized state that allows you to simply read the 16-bit conversion results and store the data by CHA0, CHB0, CHA1, CHB1... The alternative to this is to take all 18-bits from the ADS8361 SDOA (2 CH ID bits + 16-data bits) and sort the data based on the status of the channel ID bits; 00 is A0, 01 is B0, 10 is A1 and 11 is B1. See Figure 13 in the ADS8361 data sheet for details and note that the first sample should be discarded (this is Mode 1 from power-up).
Regards,
Tom
Thanks Tom, the F2000 document gives much more infos. I'll find a way to bring a GPIO signal of 6414EVM to the 8361EVM to drive M0 as required.
My apologies for the slow response here - the ADS8361 was designed for use with applications that require simultaneous sampling. The thought was customers who are trying to measure two phase currents, or the output of a sinusoidal encoder in a motor control application would find the interface 'easy' to use while incorporating the ability to capture two distinct signals at the same time. That being said, there is absolutely nothing about the part that makes it specific exclusive to a motor control application. Anywhere you need a multi-channel, high speed, high resolution ADC, the ADS8361 would definitely be an appropriate solution.
Absolutely no problem for the time, Tom, and thanks again you for your support.