1. Home
  2. Field-Programmable Gate Arrays
  3. JTAG programmers

JTAG programmers

Hi y'all,

Right, we're making some progress on parts sourcing, thanks in no small way to some of you out there who shall remain nameless to avoid embarrassment. (Thanks!)

What has come up next is the requirement for a JTAG programmer. I've found one here:

formatting link

but wonder whether using it on devices only capable of 3v3 or lower may kill them. I'm also wondering whether some of the chips I'm considering (Actel APA150, Altera EP1C3/EP1C6, Atmel AT94K05, Xilinx XC2S200E/XC3S200 and Lattice OR3T80) have particular programming needs that make a generic JTAG pod unworkable. If it merely requires level translation, I'm golden.

Comments?

Rob

Reply to
Rob Judd
Loading thread data ...

The HC part on the schematic is supplied with VCC from your board - you can also get parts with dual voltage supply that allow this type of interface, (CB3T ti parts one example). Check Altera's web site for the byteblaster MV, there are schematics for the thing up there too, and you could wire through the RESET line so that all TAP controllers would work.

Andrew.

Rob Judd wrote:

Reply to
Andrew Paule

Rob,

Even the 2.5V Vccaux parts are 3.3V JTAG compatible (ie Virtex II Pro, Spartan 3).

The JTAG inputs are designed to be 3.3V tolerant (special cells), and the JTAG outputs are open drain, and use external pullup resistors to 3.3V. The outputs are also special cells (not regular IOBs).

Aust> Hi y'all,

Reply to
Austin Lesea

Thanks, found it. That looks like exactly the thing. Now where did I put that breadboard ...

Rob

Andrew Paule wrote:

Reply to
Rob Judd

Austin,

Great news!

R

Aust>

Reply to
Rob Judd

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.