hi to all the ng
for practicing vhdl at home 3 months ago i builded a modified cable 3 and i tried to make my pc communicating with various xilinx ic's;
with cpld no problems,the cable reads and programs correctly;
but there is no way to communicate with xcv200 ,today i had the same with an xcv150,TDO looks always low.
meanwhile last time i wrote in this ng for help and today ,i bought a demo board and a cheap cable by Digilent,
with the Digilent cable(said able to work down to 1.8 V) my pc works fine with the spartan 3 on the demo board
but i am still having no result when i try to comunicate with the virtex fpgas
in this last attempt with xcv150 (PQ240,not easy to play and solder on it's pin)the fpga is mounted on a scraped board,there is a linear voltage regulator stage..i enter in it with 3.3 V
and it gives to the fpga core the 1.8 v needed
i set M0 M1 M2 at 101 to disable other modes than boundary scan(but boundary scan should be always active,in every MODE(correct?)),i cutted the tracks of the jtag so to have no conflicts
i verified that the supplies are correctly applied
PROGRAMS appears always high
anyway during boundary scan check i only see TMS and TDI high and a signal on TCK,TDO is always low :-(
any hint will be appreciated thanks to you all Diego Italy