Re: Help with Verilog: write_count

Message: 1
Date: Fri, 17 Nov 2006 09:14:28 -0800
From: Eric B.
Subject: Re: [Discuss-gnuradio] Re: Help with verilog: write_count
To: seph 004
Cc: [email protected]
Message-ID: [email protected]
Content-Type: text/plain; charset=us-ascii

On Fri, Nov 17, 2006 at 01:02:31AM -0800, seph 004 wrote:

Hi

Thanks for responding. So WR & ~write_count[8] should be able to
serve as a write enable for a ram block?

Also, while testing with one of the unmodified FPGA builds, I found
that the have_space control line would sometimes go to zero even
though I am only sending small amounts of data (60 bytes for
instance). In the original build, have_space would only go to zero
temporarily if the FIFO became full. So why then does this happen
even when sending small numbers of samples? Shouldn’t the 4k FIFO
never become full under those circumstances?

Using the standard host code, there’s no such thing as sending 60
bytes from the host. We always send 512 byte packets across the USB.

Not sure what you are doing…

Eric

Hi

I changed the host code by removing the multiplier for the “max bytes”
argument. I assumed that this would let me send the exact number of
bytes that the user entered. For my final application, I’m only looking
to store a very small number of samples on the FPGA.

If this was the wrong modification to the host code, then how exactly
would one go about sending a small number of samples (say 400 I and Q
samples) without breaking the code?

Regards

Lance


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On Sun, Nov 19, 2006 at 12:41:44PM -0800, seph 004 wrote:

Using the standard host code, there’s no such thing as sending 60
bytes from the host. We always send 512 byte packets across the USB.

Not sure what you are doing…

Eric

Hi

I changed the host code by removing the multiplier for the “max
bytes” argument. I assumed that this would let me send the exact
number of bytes that the user entered. For my final application,
I’m only looking to store a very small number of samples on the
FPGA.

If this was the wrong modification to the host code, then how
exactly would one go about sending a small number of samples (say
400 I and Q samples) without breaking the code?

You can send any multiple of 128 complex samples. No need to hack the
host library. Take your pick: 128, 256, 384, 512

Eric