Re: [casper] Interfacing 64-channel ADC with ROACH-2

[Jack Hickish]

On Mon, 4 Jul 2016 8:08 pm Kaushal Buch,  wrote:

> Hi Jack,
>
> We tried the steps mentioned by you in the earlier email with 64-channel
> ADC connected to ROACH-2 board. The following are the details of the design
> and test.
>
> #Design:
> x64_adc output was provided to MUX where it selects between counter or
> ADC input and gives to ten_gbe_v2 block. Following parameters are set:
> -XSG_core_config has been set to sys_clock 100MHz
>

This should probably by adc0 clock, at a rate 4x the adc sample clock.


> -Packet size is 4K for the 10GbE packetizer
> -ADC reset has been tried through the software register, jumper from
> GPIO(0), jumper from external source.
>
> #Tests:
>i. When MUX selects the counter input, it shows proper UDP packets
> showing the counter value as observed on Wireshark.
>ii. When MUX selects ADC data, and adc_rst of the yellow block is set
> via software register, it shows reset mode output i.e. -1(all ff...) in
> Fix_12_11 format. Packets observed were WOL(Wake-On-LAN) instead of UDP.
>iii. When GPIO(0) signal is given to reset pin of ADC by jumper
> connection, it gives reset mode output on Wireshark with WOL packets.
>iv.  When the external voltage of 2.4 V is provided to the reset pin of
> the ADC by jumper connection, it gives the same output as the reset mode
> output.
>
>
> We have the following queries with respect to the ADC board and the
> testing that was carried out.
>
>   1.  For connecting a jumper to the reset pin of the ADC board, which pin
> should be used from the ROACH-2 board? 1.5V from GPIO is not sufficient to
> drive the reset pin of ADC. How to use the GPIO(0) pin in this case?
>

Good point. I suppose you'll need to change the levels using your own
hardware. Roach1 didn't have this problem.



>   2. Do we need an external supply voltage to reset the ADC board? If so,
> what should be the voltage level?
>

I think for roach2 you'll need to get the levels up to what they were on
roach 1 (3.3V?). The adc schematics, if online, should confirm the correct
level.


  3. What should the clock selection be for XSG_core_config settings,
> sys_clock or adc_clock, or both possible?
>

adc_clk0. The FPGA has to be synchronous with the ADC.


>   4. WOL packets indicate power-down mode of ADC, so is there a way to
> check the digitized output at the ZDOK connector?
>

There's no way to check, unless you mess with the interface verilog. All
-1's signify a reset problem though, so I would expect that is genuinely
what's coming over the zdok.

J



>
>
> Thanks & Regards,
>
> Kaushal
>
> On Wed, Jun 8, 2016 at 11:33 PM, Jack Hickish 
> wrote:
>
>> Hi Kaushal, cc. CASPER,
>>
>> All good here (Berkeley), thanks. Hope you are well too.
>>
>> It's been a long time since I've used that ADC, but from what I
>> remember...
>>
>> - Yes, you need to appropriately drive the ADC's reset through the
>> jumper. If things aren't working and you're debugging with a probe, note
>> that this reset is active low.
>> - the yellow block uses GPIO[0] for the ADC's reset. On ROACH, you had
>> the choice between gpio banks A and B. On ROACH2, this option on the yellow
>> block doesn't do anything.
>> - If you're using the SPI interface, the yellow block uses GPIOs 1,2,3
>> for data, clk, and cs_n, respectively.
>> - The ADC reset is controlled by the active high reset input on the
>> yellow block, which is inverted and drives GPIO[0]. I suggest tying this to
>> a software register.
>>
>> There are more details at https://casper.berkeley.edu/wiki/X64_adc
>>
>> Don't forget there's some link calibration stuff you need to do --
>> details are on that wiki page.
>>
>> Let me know if you have other questions,
>>
>> Cheers
>>
>> Jack
>>
>>
>> On Wed, 8 Jun 2016 at 06:07 Kaushal Buch  wrote:
>>
>>> Dear Jack,
>>>
>>> Hope you are doing good.
>>>
>>> We have recently purchased 64-channel ADC boards and are planning to use
>>> them with ROACH-2. We have a basic design developed for packetizing the
>>> data and sending it on 10GbE port.
>>>
>>> I have gone through the available literature for this on the internet.
>>> However, I need some additional confirmation with reference to the
>>> 64-channel ADC board:
>>>
>>> 1. Is it mandatory to reset the ADC through jumper  ? If yes, which pin
>>> should it be connected to on the ROACH-2 board ?
>>>
>>> 2. Can we reset the ADC via software register or GPIO ? In this case,
>>> how to configure the GPIO ?
>>>
>>>
>>>
>>> Thanks & Regards,
>>>
>>> Kaushal
>>>
>>
>

Re: [casper] Interfacing 64-channel ADC with ROACH-2

[Jack Hickish]

Hi Kaushal, cc. CASPER,

All good here (Berkeley), thanks. Hope you are well too.

It's been a long time since I've used that ADC, but from what I remember...

- Yes, you need to appropriately drive the ADC's reset through the jumper.
If things aren't working and you're debugging with a probe, note that this
reset is active low.
- the yellow block uses GPIO[0] for the ADC's reset. On ROACH, you had the
choice between gpio banks A and B. On ROACH2, this option on the yellow
block doesn't do anything.
- If you're using the SPI interface, the yellow block uses GPIOs 1,2,3 for
data, clk, and cs_n, respectively.
- The ADC reset is controlled by the active high reset input on the yellow
block, which is inverted and drives GPIO[0]. I suggest tying this to a
software register.

There are more details at https://casper.berkeley.edu/wiki/X64_adc

Don't forget there's some link calibration stuff you need to do -- details
are on that wiki page.

Let me know if you have other questions,

Cheers

Jack


On Wed, 8 Jun 2016 at 06:07 Kaushal Buch  wrote:

> Dear Jack,
>
> Hope you are doing good.
>
> We have recently purchased 64-channel ADC boards and are planning to use
> them with ROACH-2. We have a basic design developed for packetizing the
> data and sending it on 10GbE port.
>
> I have gone through the available literature for this on the internet.
> However, I need some additional confirmation with reference to the
> 64-channel ADC board:
>
> 1. Is it mandatory to reset the ADC through jumper  ? If yes, which pin
> should it be connected to on the ROACH-2 board ?
>
> 2. Can we reset the ADC via software register or GPIO ? In this case, how
> to configure the GPIO ?
>
>
>
> Thanks & Regards,
>
> Kaushal
>