How many A/D inputs?

[nitron]

Hello,

The Zynq family is equipped with 2, 12bits ADC, 1 Msample/s each with up to 17 differential inputs...

How many analogue inputs (single ended or differential) will be available on the Parallella board connectors?
Is it possible to configure some FPGA GPIOs as analogue inputs (seems very uncertain to me...) ?
Is it correct to say that the Parallella board has no possible analogue inputs?

Other solutions in order to use the A/D converter ?

Regards,
Cristian

[timpart]

It seems that at least some versions of the board have a single differential ADC input on PEC Power pins 33 and 34 (VADC_N and VADC_P). Older development versions have a voltage there. I expect Adapteva can clarify whether boards that are shipping have this.

Tim

[rjsdotorg]

Are there any code examples of using the ADCs here? I couldn't Google any.

If the sample rate was 500kHz, say, are there any resources left for significant processing?

[fdeutschmann]

The Zynq XADC inputs that are mappable are all in Bank 35; unfortunately, the Parallella uses Bank 35 for implementing the eLink to the Epiphany chip, so the 16 mappable XADC diff pairs are effectively unavailable on the Parallella. (Per the Rev1 schematics published; the Parallella GPIO pins come from Banks 34 & 13.)

The Zynq internal sensors are of course available, and the Parallella Rev1 has the one fixed assignment XADC input diff pair on the PEC Power connector. No idea if these are enabled in the Parallella bitstream, though; the XADC can be configured in a lot of different ways.

If you set up the bitstream correctly, you could access the fixed assignment XADC diff pair and the internal sensors from Linux; the Parallella has plenty of compute power to process a 500 KHz signal, from the Epiphany to the ARM cores to FPGA processing.

-frank

[rkanchan]

Hello,
I am looking for possible solutions to interface to XADC inputs on Paralella board. What a pity that it might not be possible with exiting version of the board. Correct me if their is any alternate way!!! Has anyone tried modifications to achieve above or it is just impossible since this pins (Zynq Bank 35) is hardcoded for eLink interface??
reg.
rkanchan