Re: [Discuss-gnuradio] [USRP-users] what is the largest data transfer rate between fpga and overo in e100

[Philip Balister]

On 05/30/2012 11:46 AM, Ian Buckley wrote:
> There is a mictor connector (J301 on both USRP2 and N2x0) that has 32 signal 
> and 2 clock pins all free to be used in the FPGA. Searching for "mictor" in 
> the archive of this forum will find other posts about this.
> 
> However I do want to drive home the point  that you are unlikely to find an 
> ARM processor currently that is capable of doing anything useful directly 
> with RF data at bandwidths greater than which the E100 is capable or indeed 
> one with a flexible physical interface that can support 60MB/s....you're 
> clearly in the realm of high-end DSP processors at those rates.

If you need to do the processing on an ARM, you should research this
company:

http://www.calxeda.com/products/energycards/quadnode

Philip

> 
> 
> On May 30, 2012, at 8:02 AM, Almohanad Fayez wrote:
> 
>> I don't believe there's a document for this it's more of an exercise left 
>> for the motivated user.
>>
>> On May 30, 2012 6:27 AM, "Page Jack" <address@hidden> wrote:
>> Hi Almohanad ,
>> thanks for this information, can you provide more detail or is there any doc?
>>
>> On 5/30/12, Almohanad Fayez <address@hidden> wrote:
>>> If memory serves correctly the n200 or the usrp 2 has an fpga expansion
>>> interface to some xilinx development platform which you might be able to
>>> use to create a custom solution to serve your needs.
>>>
>>> Al
>>> On May 29, 2012 6:17 PM, "Page Jack" <address@hidden> wrote:
>>>
>>>> I don't want to using a ethernet wire to connect N series to an ARM
>>>> board.
>>>> anyone have tried
>>>> build N series with ARM or DSP in one board which means the ethernet line
>>>> between N and
>>>> the processor is on PCB.
>>>>
>>>> On Wed, May 30, 2012 at 6:24 AM, Philip Balister
>>>> <address@hidden>wrote:
>>>>
>>>>> On 05/25/2012 09:18 PM, Page Jack wrote:
>>>>>> Hi Philip,
>>>>>> How does the conclusion be made that ARM can not swallow the current
>>>>>> max data transfer rate? I need to build a project that need to process
>>>>>> 60MB/s data, so any way to achieve my goal. Use a more powerful CPU or
>>>>>> use dsp on the omap?
>>>>>
>>>>> 60 MB/s is far more data than the OMAP3 can transfer from the FPGA. We
>>>>> have worked hard on configuring the GPMC interface and this figure is
>>>>> basically an order of magnitude more then the hardware will support.
>>>>>
>>>>> You need to look at the N series with Gig-E, or do the high rate
>>>>> processing in the FPGA.
>>>>>
>>>>> Philip
>>>>>
>>>>>
>>>>>>
>>>>>> On 5/25/12, Philip Balister <address@hidden> wrote:
>>>>>>> On 05/24/2012 09:46 PM, Page Jack wrote:
>>>>>>>> Thanks Ben,
>>>>>>>> does e100 use EMIF to transfer sample data between FPGA and ARM? If
>>>>>>>> so
>>>>>>>> the
>>>>>>>> data rate should be able to improved.
>>>>>>>> Anyone have tried to improve the data rate?
>>>>>>>
>>>>>>> EMIF is basically identical to GPMC. The interface uses DMA to move
>>>>> data
>>>>>>> in 2K chunks between the FPGA and memory. This is the largest
>>>>>>> transfer
>>>>>>> possible due to how we connected the address and data lines
>>>>>>>
>>>>>>> My impression of the current limiting factor is interrupt response
>>>>> time.
>>>>>>> There is probably some room for small improvements, but as Ben notes,
>>>>> we
>>>>>>> are already collecting data faster than the ARM can swallow it.
>>>>>>>
>>>>>>> Philip
>>>>>>>
>>>>>>>>
>>>>>>>> Regards
>>>>>>>>
>>>>>>>> On Thu, May 24, 2012 at 9:01 AM, Ben Hilburn <address@hidden>
>>>>>>>> wrote:
>>>>>>>>
>>>>>>>>> The CPU sets up the initial DMA parameters, but from then on, it's
>>>>> pure
>>>>>>>>> DMA.  No CPU is required.
>>>>>>>>>
>>>>>>>>> Cheers,
>>>>>>>>> Ben
>>>>>>>>> ----------------------------
>>>>>>>>> Ben Hilburn <http://goo.gl/5DdZ3> @ Ettus Research,
>>>>>>>>> LLC<http://www.ettus.com/>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Wed, May 23, 2012 at 5:55 PM, Page Jack <address@hidden>
>>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>> Thanks, does the ARM memory bus use DMA or it eat cpu?
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Thu, May 24, 2012 at 5:06 AM, Ben Hilburn
>>>>>>>>>> <address@hidden>wrote:
>>>>>>>>>>
>>>>>>>>>>> Page -
>>>>>>>>>>>
>>>>>>>>>>> The memory bus to the ARM provides 40 MBytes / second.  This is
>>>>> used
>>>>>>>>>>> for
>>>>>>>>>>> streaming samples, as controlled via software.  Currently, UHD
>>>>> supports
>>>>>>>>>>> 16
>>>>>>>>>>> bit and 8 bit samples for TX & RX.  The GPMC can only going to
>>>>> talk to
>>>>>>>>>>> one
>>>>>>>>>>> slave at a time; the possible slaves are TX, RX, and ethernet.
>>>>>>>>>>> So
>>>>> you
>>>>>>>>>>> can
>>>>>>>>>>> only be sending TX samples, receiving RX samples, or
>>>>>>>>>>> communicating
>>>>> via
>>>>>>>>>>> ethernet.
>>>>>>>>>>>
>>>>>>>>>>> Thus, doing the math with the numbers above, you can stream:
>>>>>>>>>>> 16 bit I, 16 bit Q -- Total: 32-bit samples -- @ 10 MSps
>>>>>>>>>>> 8 bit I, 8 bit Q -- Total: 16-bit samples -- @ 20 MSps
>>>>>>>>>>>
>>>>>>>>>>> What you choose to do with this data is obviously up to you. It
>>>>>>>>>>> is
>>>>>>>>>>> very
>>>>>>>>>>> easy to try to do more processing than the ARM can handle, in
>>>>>>>>>>> which
>>>>>>>>>>> case
>>>>>>>>>>> samples will start getting thrown out by UHD.  Thus, you can
>>>>> typically
>>>>>>>>>>> process between 4 and 8 MHz of baseband bandwidth, depending on
>>>>> your
>>>>>>>>>>> application.  If you are willing to dig deep into the code to
>>>>>>>>>>> make
>>>>> NEON
>>>>>>>>>>> and
>>>>>>>>>>> C64 optimizations, you can improve the performance dramatically.
>>>>>>>>>>>
>>>>>>>>>>> Cheers,
>>>>>>>>>>> Ben
>>>>>>>>>>> ----------------------------
>>>>>>>>>>> Ben Hilburn <http://goo.gl/5DdZ3> @ Ettus Research,
>>>>>>>>>>> LLC<http://www.ettus.com/>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Tue, May 22, 2012 at 7:47 PM, Page Jack
>>>>>>>>>>> <address@hidden>wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Hi,
>>>>>>>>>>>> I want to know the overo model used in e100 and the largest data
>>>>>>>>>>>> transfer rate between fpga  and overo in e100.
>>>>>>>>>>>>
>>>>>>>>>>>> Regards!
>>>>>>>>>>>>
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>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
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