[Discuss-gnuradio] Re: About Latency

[KC Huang]

Hi Eric:

I have already read that paper before. As that paper mentions, the USB delay 
is according to the equation

f(512, fusb_block_size*fusb_nblock)
-------------------------------------
fs*sample_size                                                     , which 
f(x,y) is at least x and at most y

So, does that mean if u have large product of fusb_block_size and 
fusb_nblock, then the theometical maximum delay will be increased? 
Therefore, I think that the range of USB latency is also increased. Please 
correct me if I am wrong. Thanks!

KC

----- Original Message ----- 
From: "Eric Blossom" <address@hidden>
To: "KC Huang" <address@hidden>
Cc: <address@hidden>
Sent: Friday, October 05, 2007 8:29 AM
Subject: Re: About Latency


> On Thu, Oct 04, 2007 at 03:22:40PM -0400, KC Huang wrote:
> > Hi all:
> >
> > I have two questions about Gnuradio latency:
> >
> > 1. In transmit path, the USB delay is constant due to the 32KB buffer
> > between "signal source output" and "USB".
>
> You misunderstand how things work.
>
> Please take a look at Thomas Schmid's paper
> http://nesl.ee.ucla.edu/document/show/242
> and then if you've still got questions, please post again.
>
> Eric