Re: [fpga-cpu] Xilinx bitgen problem

Started by Guil...@h... January 5, 2001
Hi!

Maybe what I'm going to said is stupid, but "the clk has no source"....
What clk is that???
Are you using the fpga external clock???
If you are not, I think you my try it, by using pin 13.
That's what I think... sorry if it's dumb... hehe ;P
Thanks for listening...

Jorge, Guilherme
----- Original Message -----
From: "Bharath Kumar" <bharath.kumar@w...>
To: <f...@egroups.com>
Sent: Thursday, January 04, 2001 6:58 AM
Subject: [fpga-cpu] Xilinx bitgen problem > hi All,
> I tried my first design using design manager yesterday...
> I was able to succesfully complete the flow upto Place and Route(PAR)....
but
> "Bitgen" is giving some problem as follows:
>
****************************************************************************
*********
> Running DRC
> ERROR:DesignRules:368 - Netcheck: Sourceless. Net clk has no source.
> ERROR:DesignRules:10 - Netcheck: The signal "clk" is completely unrouted.
>
****************************************************************************
*************
>
> I couldnt get the exact meaning of the above message...Please help me.
>
> thanks and Regards,
> Bharath
> Bangalore, INDIA >
>
> To Post a message, send it to: f...@eGroups.com
> To Unsubscribe, send a blank message to: f...@eGroups.com




Not really sure what the original requirement is as I've just joined
this group, but if it's to connect a PIC to a receiver so you can get
the PIC to perform a function on receipt of a signal from the
transmitter (like the speed of a motor or turn on some light) then there
are loads of CCts and code available on the web. If on the other hand
the object is to read the PPM signals from the transmitter for use as a
flight sim interface, then again there are lots of examples of how to do
this on several web sites (including my own electronics site
www.rc-electronics.net )

My experience is that each channel signal is a pulse with a width of
between 1ms and 2.0ms, with 1.5ms being the centre point on the servo
travel. Thus with a 6 channel TX you have a train of six pulses between
1 and 2 ms with a sync puls at the end of the frame. (at least this is
the case with Futaba and JR transmitters). These pulses are repeated in
a 20ms time frame. With this sort of timing you can use the internal
oscillator in most PICs if you want to read the signals in a project
such as an RC switch. However if you are interfacing with a PC you need
the precision of an external crystal or resonator to maintain the data
stream to the PC

Regards Malcolm

Michael Shiloh wrote:

> It's my understanding that this is not a standard. Some transmitters
> overlap a bit, e.g. an 8 channel transmitter might transmit at the
> same time channels 1 and 5, 2 and 6, 3 and 7, and 4 and 8.
>
> Another variation is when a pulse will start; sometimes channel 2 will
> go high at the same time that channel 1 goes low; in other transmitters,
> channel 2 may go high 2 msec after channel 1 goes high, regardless of
> how long the channel 1 pulse lasted.
>
> I've always written my decoders so that each channel is decoded
> independently. This also allows changing channels by moving connectors,
> without having to worry about whether that confuses the decoding
> algorithm. I've had to do this moments before a performance ( I do
> controllers for large scale R/C machine performances) and been pleased
> that I didn't have to reprogram anything.
>
> Michael > On Fri, 28 Jan 2005 wrote:
>
> >
> > In a message dated 1/28/2005 12:45:56 PM Eastern Standard Time,
> > writes:
> >
> > Also, it somewhat depends on how the RC pulses come in. Do they all
> > start at the same time or are they staggered?
> >
> >
> >
> >
> >
> > They come in as a pulse train. The PIC only has to decode one
> channel at a
> > time. PIC's work very nicely for decoding R/C.
> >
> > Randy
> > _www.soaringcircuits.com_ (http://www.soaringcircuits.com)
> <http://www.soaringcircuits.com%29>
> >
> > to unsubscribe, go to http://www.yahoogroups.com and follow the
> instructions >
> *>.




--- In , "meriachee" <meriachee@y...> wrote:
>
> Thank you. What if you are using the pin for something else though?
>
> Pardon me, but I came to this from using Oopic where you didn't
need
> anything else...

That's where the 'almost' comes in. There are chips where the MCLR
line can be used for IO, in which case, there is no external MCLR
function. But, if the pin is used for input, it must still be
terminated properly.

So, read the datasheet and follow the instructions. They're pretty
clear about how to handle this.

And it isn't true that the OOPic world doesn't concern itself with
this. The same rules apply - don't allow input signals to float.

>
> --- In , "rtstofer" <rstofer@p...> wrote:
> >
> >
> > Almost always... Just assume it does.
> >
> > --- In , "meriachee" <meriachee@y...>
wrote:
> > >
> > > That should, of course, be 16f818.
> > >
> > >
> > > --- In , "meriachee" <meriachee@y...>
> wrote:
> > > >
> > > > Hello,
> > > >
> > > > I'm using the internal osc from the PicProgrammer site,
> > > >
> > > > The Code Fix:
> > > > PicBasic Compiler:
> > > > Symbol OSCCON = $8F
> > > > Poke OSCCON, $60
> > > >
> > > > and the code is the first attempt at making this chip go:
> > > >
> > > >
> > > > loop: High 0 'Turn on LED connected to RB0
> > > > Pause 500 'Delay for .5 seconds
> > > >
> > > > Low 0 'Turn off LED connected to RB0
> > > > Pause 500 'Delay for .5 seconds
> > > >
> > > > Goto loop 'Go back to loop and blink LED
forever
> > > > End
> > > >
> > > >
> > > > Of course the chip does not run.
> > > >
> > > > Does it need a 4k7 on the mclr line to +5?
> > > >
> > > > Gary




Can't erase 16F877
hi
i hav a used 16F877.
when i try to read after erase it show
"Device is data protected! Data memory may be
invalid.

Device is code protected! Program memory may be
invalid"
is this is the progblem of my PIC?
i had try the 10k on RB3/PGM on the 36th pin and Gnd.
still have the same message

what should i do
thanks
__________________________________



you can try useing high volt programming mode to turn off "Code Protect" in the
configuration byte. Quoting sandeep c p <>:

>
> hi
> i hav a used 16F877.
> when i try to read after erase it show
> "Device is data protected! Data memory may be
> invalid.
>
> Device is code protected! Program memory may be
> invalid"
> is this is the progblem of my PIC?
> i had try the 10k on RB3/PGM on the 36th pin and Gnd.
> still have the same message
>
> what should i do
> thanks >
> __________________________________ > to unsubscribe, go to http://www.yahoogroups.com and follow the
> instructions
> Yahoo! Groups Links



i try the HV mode.still have the same problem.
thanks
__________________________________