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Altera_Forum
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13 years ago

Problem with JTAG

Hi, I use an USB Blaster cable to program an EP3C25U256 an EPCS16 with quartus II web edition 11.1. First, I programmed several times without any problem and after a while, i received an error ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

A short circuit between TDI and GND could indicate another kind of fail, such as an ESD or overvoltage on the pin itself. How is the board JTAG interface designed? Is it a direct connection from the connector to the JTAG FPGA pins or is there a buffer between the two? What I/O voltage standard is used? Do you have protection diodes in parallel?

Do you connect your board to the USB blaster in a lab with proper ESD protection? Try to earth both the board and the USB blaster gnd pin before you plug it in.