ADSP-CM408F and AD1938/1939, SPORT I2S handling

Folks,

Has anyone ever dealt with the new Analog Devices ADSP-CM processor series in connection with a codec such as the AD1938 which uses SPORT I2S?

According to our software engineer there isn't much in terms of examples available and we are right now mostly trying to get our hands around which signal connections we need and then how to best go about creating a driver.

We need to operate in full duplex at 48ksps on all four ADC channels and on two DACs (but as AFAIU it has to internally run 8ch/8ch for that with lots or zeroes).

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg
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Joerg:

I2S?

examples

creating

and

with

Which processor are you using (exact part number) - I've looked at these for a client but I'm waiting until they have actually got them for sale from distribution before doing any more work. If you really have to start design work so early I'd be really tempted to put a little FPGA between the uP and the AD1938 so that the bridge between AD's actual silicon and your intepretation of their intentions can be bridged.

MK

Reply to
Michael Kellett

Michael Kellett:

SPORT

these

sale

I meant to say:

so that the gulf between AD's actual silicon and your intepretation of their intentions can be bridged

MK

Reply to
Michael Kellett

We are using the ADSP-CM408F. Later we might back off to a less powerful version but only after we know how heavy the processor workload ends up being.

That has me concerned a wee bit as well, considering that it's been more months than usual from announcement to devices showing up in the sales channels. But when adherig to the CMSIS libraries for the most part it should not be too difficult to switch to another brand in case things hit the fan.

It's a small team, essentially me and a SW engineer. Neither of us is very used to FPGA so we'll do the Sauerkraut thing. Lots of non-install resistors that can be used as a switchboard. So far it seems we can run full duplex on just ABCLK, ALRCLK, ASDATA1 and DSDATA1. The B clocks from the ADSP-CM408F will be ferried over via resistors in case the shunting inside the ARM processor won't work for some reason (according to AD it should).

Right now we are using their EZ-Kit boards to save some NRE and to get to a prototype stage early. Later we'll ditch all unwanted stuff and make a single clean board. With or without the ADSP, depending on product availability. But definitely with the AD1938 because that has DC-capability.

:-)

What was a bit disappointing is the scarcity of example code and obtaining answers seems to take a long time. Some of the advertised features such as USB aren't really available unless one buys an expensive RTOS license on top of the fat four digits we paid for the compiler. So we'll be using SCADA software via RS232 for the GUI.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Den mandag den 27. april 2015 kl. 22.16.24 UTC+2 skrev Joerg:

it wouldn't suprise me if the SPORTs are reuse of something used in something like blackfin. So Id look there first

a scope/logicanalyser lots of coffee and it shouldn't be too hard, the AD SPORTs are generally very flexible

-Lasse

Reply to
lasselangwadtchristensen

We are essentially copying methods from a Blackfin implementation because that seems to be the only available information right now. We'll be using TDM.

And one Guinness in the evening :-)

Also, both at the SW engineer and at my lab we are working under strict canine supervision which helps.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

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