From: ucfchuck on
i wrote an xsvf player bridged across a pc and an fx2lp to deliver the
program code to a prom through a gpio port on the fx2lp. it works fine and
will reprogram a system and will program a new system. but when it is an
encrypted sourcefile the key has to already be in the system, and i cannot
program it from the player. there are no new commands that i can see which
are not in the regular program file, though the xsvf does show some strange
duplication of commands, im guessing to send the device into the special
programming mode.

point is i can program 7+MB of data over this player just fine, but
700bytes wont work? theres obviously something there that i cant find in
any documentation, as the key is programmed fine when i use impact and the
cable to play the xsvf file. i cant exactly find out what is different bit
by bit as xilinx has their cable set to pseudo random delays so a scope is
just a pain.

has anyone gotten through this mess before? whats the problem with writing
a key through the xsvf?

Posted through
From: Marc Jet on
Impact generates a TDO VERIFY command with incorrect data. If your
player verifies, it will stop and complain early into the file.

I count the verify commands that appear in the file, and only really
honor the first two (during key programming). That works for me.