#81 SVF compare_tdo flaw?

[Kolja Waschk]

The svf_compare_tdo function fails on a particular instruction in an Actel SVF file, although I think it should NOT.

SDR 32 TDI(00000000) TDO(03A121CF) MASK(06FFFFFF);

This should check the IDCODE, which is actually 02A121CF. The svf_compare_tdo reports a mismatch at position 31. The comparison seems to XOR a decimal value with a ASCII value, possibly?

Kolja

[Kolja Waschk]

I suggest the following change:

--- svf.c (revision 1407)
+++ svf.c (working copy)
@@ -437,7 +437,7 @@

mismatch = -1;
for (pos = 0; pos < reg->len; pos++)
- if ((svf_hex2dec(tdo_bit[pos]) ^ reg->string[pos]) & svf_hex2dec(mask_bit[pos]))
+ if ((tdo_bit[pos] != reg->string[pos]) && (mask_bit[pos] == '1'))
mismatch = pos;

[Kolja Waschk]

[Arnim Läuger]

Whew, nasty bug. Wonder how that could slip through for such a long time.
Patch looks good BTW.

Arnim

[Kolja Waschk]

Committed in 1410.