RE: [Discuss-gnuradio] Default FPGA I/O standard

[Bahn William L Civ USAFA/DFCS]

> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On Behalf
> Of Brian Padalino
> Sent: Monday, October 01, 2007 5:53 PM
> To: Matt Ettus
> Cc: address@hidden
> Subject: Re: [Discuss-gnuradio] Default FPGA I/O standard
>
> On 10/1/07, Matt Ettus <address@hidden> wrote:
> > I think 3.3V LVTTL and LVCMOS are really the same.
> >
> > Matt
>
> According to this:
>
>     http://www.interfacebus.com/voltage_LV_threshold.html
>
> They are, indeed, basically the same.
>
> Brian

They're the same only different.

For most purposes, the differences don't matter too much. The biggest 
difference is in the output drive capability. LVTTL outputs are required to be 
able to source/sink 2mA while remaining compliant while LVCMOS outputs are only 
required to source/sink 100uA.

For those interested in the "official" word, refer to the actual JEDEC standard:

http://www.jedec.org/download/search/jesd8c.pdf