Dangerous Prototypes

Hi all,

I'm trying to program a spartan a3s400 using urJtag on a Raspberry Pi 3.
I've set the M[0 ... 2] pins (configuration mode=JTAG) to 101 on the board.
When I run svf command, I get the following error.

jtag> cable gpio tdo=9 tdi=10 tck=11 tms=25
Initializing GPIO JTAG Chain
jtag> detect
IR length: 14
Chain length: 2
Device Id: 00000001010000011100000010010011 (0x0141C093)
  Manufacturer: Xilinx (0x093)
  Part(0):      xc3s400 (0x141C)
  Stepping:     0
  Filename:     /usr/local/share/urjtag/xilinx/xc3s400/xc3s400
Device Id: 11110101000001000101000010010011 (0xF5045093)
  Manufacturer: Xilinx (0x093)
  Part(1):      xcf02s (0x5045)
  Unknown stepping! (1111) (/usr/local/share/urjtag/xilinx/xcf02s/STEPPINGS)
jtag> part 0
jtag> print
 No. Manufacturer              Part                 Stepping Instruction          Register
-------------------------------------------------------------------------------------------------------------------
   0 Xilinx                    xc3s400              0        BYPASS               BR
jtag> svf a.svf progress stop
requested frequency 1000000, now calibrating delay loop
new real frequency 60620.6, delay 1
new real frequency 60943.1, delay 0
operating without delay
done
Error svf: mismatch at position 31 for TDO
 in input file between line 22 col 1 and line 22 col 72
error: Error occurred for SVF command, line 21, column 0-71:
 SDR.
detail: Parsing   3490/3494 ( 99%)detail:
detail: Mismatches occurred between scanned device output and expected TDO values.
jtag>

I tried changing the frequency but it didn't help.
I don't know what may cause this problem, and google couldn't help me more :D
Can somebody please help me?

Hi grcg,

    I'm no expert, but it seems like there's something not lining up between your SVF file and the hardware.  As I understand things, the SVF is just a list of JTAG commands and their expected results.  UrJTAG is telling you that it got a different result from the hardware vs what the SVF says.

So, perhaps it's worth starting with some more basic debugging - maybe try toggling IO pins on the Spartan over JTAG or something along those lines.  If that works, then have a look at the process that creates your SVF file.    -Ian-