[time-nuts] An embedded NTP server

Jim Lux jimlux at earthlink.net
Fri Dec 28 18:09:32 UTC 2012

On 12/28/12 9:34 AM, Chris Albertson wrote:
> On Thu, Dec 27, 2012 at 1:36 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
> One idea that I like is to first get a large FPGA.  Then you load in a
> "soft CPU" and then you run an OS and NTP on the soft CPU.   Inside
> the softCPU the counter is implemented like it is in a real CPU but
> you can add the ability for a PPS to "latch" it.  Basicaly you move
> the interrupt handler to hardware.     The trick is if you can get
> good enough performance out of the soft CPU?    There is some
> intelectual property problems with some soft CPS but I'm pretty sure
> there are free SPARC CPS you can use and SPARC is ideal for this as it
> can run BSD Unix.

The LEON core for the SPARC V8 is free and available from gaisler.com. 
The free version doesn't come with testbenches or support, but all the 
source and documentation is there.  There's a fairly active mailing list 
for support with participation by the guys who implemented the core.

It's a fairly easy "drop in" to either Xilinx or Actel FPGAs, and it's 
configurable (e.g. if you don't want floating point you don't compile it 

There is are several prebuilt versions of *nix as well as RTEMS for the 
core on the gaisler website as well.  There's a IPv4 stack for RTEMS, 
derived from the BSD stack.

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