XST and LogiCORE Turbo Product Code Encoder and Decoder (TPC) - How can I get the TPC to compile using XST, without incurring MAP Pack ERROR:Pack:679?
Description
Keywords: Virtex, XST, Synplify
How can I get the TPC to compile using XST, without incurring MAP Pack ERROR:Pack:679?
******************************************************************************
ERROR:Pack:679 - Unable to obey design constraints (MACRONAME=hset, RLOC=X0Y0)
which require the combination of the following symbols into a single SLICE
component:
LUT symbol "U_tpc_fifo/U0/U00" (Output Signal = U_tpc_fifo/U0/_n0001)
LUT symbol "U_tpc_fifo/U0/U01" (Output Signal = U_tpc_fifo/U0/z0<1>)
MUXCY symbol "U_tpc_fifo/U0/U10" (Output Signal = U_tpc_fifo/U0/c0<1>)
MUXCY symbol "U_tpc_fifo/U0/U11" (Output Signal = U_tpc_fifo/U0/c0<2>)
XORCY symbol "U_tpc_fifo/U0/U20" (Output Signal = U_tpc_fifo/U0/_n0006)
XORCY symbol "U_tpc_fifo/U0/U21" (Output Signal = U_tpc_fifo/U0/d0<1>)
FLOP symbol "U_tpc_fifo/U0/U30" (Output Signal = U_tpc_fifo/write_addr<0>)
FLOP symbol "U_tpc_fifo/U0/U31" (Output Signal = U_tpc_fifo/write_addr<1>)
Signal `U_tpc_fifo/U0/c0<1>' has a NOMERGE parameter. Please correct the
design constraints accordingly.
******************************************************************************
Solution
XST has a problem with the way the "syn_keep" is used for the carry chains in the "up_counter.vhd" and "down_counter.vhd".To work around this issue, comment out the following lines:
- attribute syn_keep of c0 : signal is true;
- Line 91 in up_counter.vhd
- Line 91 in down_counter.vhd
- attribute BEL of U0 : label is bel_lut(i mod 2);
- attribute BEL of U2 : label is bel_xor(i mod 2);
- Lines 89 and 90 in subtract.vhd
For a detailed list of LogiCORE Turbo Product Code (TPC) Decoder Release Notes and Known Issues, see (Xilinx Answer 30178).
For a detailed list of LogiCORE Turbo Product Code (TPC) Encoder Release Notes and Known Issues, see (Xilinx Answer 30179).