Gabor <gabor@alacron.com> wrote in message
1194361400.851894.46660@y42g2000hsy.googlegroups.com...
> On Nov 6, 6:20 am, "blisca" <bliscachiocciolinatiscali.it> wrote:
> > Hi ,i like to use cpld and fpgas scraped by boards at home at the
purpose of
> > practicing VHDL.
> > I have some Spartan 3    XC3S1500,and an inexpensive Digilent JTAG cable
> > rated 1.8 to 5.5 V.
> > There is some trick to use it for programming a Spartan 3 ,having a core
> > voltage of 1,2V?
> > Thanks
> > Diego,Italy
>
>
> The programming cable does not interface to the core voltage of the
> FPGA, only the I/O voltage for the JTAG.  In some parts this is a
> separate JTAG or Auxiliary supply voltage.  On other parts it may
> be Vcco for a particular bank.  Usually it is in the range of 1.8
> to 3.3V so there is no issue with the Digilent cable in this regard.
>
> I'm not familiar with the Digilent cable, but the Xilinx parallel
> cables have a pin for the interface voltage usually labelled Vcc
> that must be connected to the I/O voltage of the devices to be
> programmed.
>
> HTH,
> Gabor

Many thanks,maybe i was misleaded by the fact that 1,8 V looks like a core
voltage

On Nov 6, 6:20 am, "blisca" <bliscachiocciolinatiscali.it> wrote:
> Hi ,i like to use cpld and fpgas scraped by boards at home at the purpose of
> practicing VHDL.
> I have some Spartan 3    XC3S1500,and an inexpensive Digilent JTAG cable
> rated 1.8 to 5.5 V.
> There is some trick to use it for programming a Spartan 3 ,having a core
> voltage of 1,2V?
> Thanks
> Diego,Italy


The programming cable does not interface to the core voltage of the
FPGA, only the I/O voltage for the JTAG.  In some parts this is a
separate JTAG or Auxiliary supply voltage.  On other parts it may
be Vcco for a particular bank.  Usually it is in the range of 1.8
to 3.3V so there is no issue with the Digilent cable in this regard.

I'm not familiar with the Digilent cable, but the Xilinx parallel
cables have a pin for the interface voltage usually labelled Vcc
that must be connected to the I/O voltage of the devices to be
programmed.

HTH,
Gabor

Hi ,i like to use cpld and fpgas scraped by boards at home at the purpose of
practicing VHDL.
I have some Spartan 3    XC3S1500,and an inexpensive Digilent JTAG cable
rated 1.8 to 5.5 V.
There is some trick to use it for programming a Spartan 3 ,having a core
voltage of 1,2V?
Thanks
Diego,Italy