QUES: ODFX/IDFX inferred in syplify, and not in XACT libraries ????

[Ted]

I have to make changes to an old legacy product containing an XC4005
part.
I was able to find a set of old XACT tools but the problem is that the
newer
synplify versions infer the primitives IDFX and ODFX. These to
primitives
are NOT included in the XC4000 libriaries and I have not been been
able
to get past the xnfmerge step. I looked at the xnf file and the ODFX
and
IDFX primitives are D-Flip-flops with enable. But when I look at the
logic
there is no enable needed. Syplicity ties the enable to VCC. For
example,
the following proccess,

PROCESS(clk27m)
BEGIN
IF RISING_EDGE(clk27m) THEN
d1data <= d1data_in;
END IF ;
END PROCESS;

gets mapped to the following in the xnf file,

SYM, d1data_in_inff<1>, IFDX, LIBVER=2.0.0
PIN, Q, O, d1_in/d1data<1>
PIN, D, I, d1data_in<1>
PIN, C, I, clk27m_c
PIN, CE, I, VCC


Is there a way to get synplify to infer the IFD primitive (D-flop w/o
enable) instead of the IFDX without making the source vender specific
or hacking the xnf file?? Does
anyone know where I can get older versions of Syplicity synplify (pre
6.0)? Thanks for any info.

Ted

 

[Philip Freidin]

I have to make changes to an old legacy product containing an XC4005 part.
I was able to find a set of old XACT tools but the problem is that the newer
synplify versions infer the primitives IDFX and ODFX. These to primitives
are NOT included in the XC4000 libriaries and I have not been been able
to get past the xnfmerge step. I looked at the xnf file and the ODFX and
IDFX primitives are D-Flip-flops with enable. But when I look at the logic
there is no enable needed. Syplicity ties the enable to VCC. For example,
the following proccess,

PROCESS(clk27m)
BEGIN
IF RISING_EDGE(clk27m) THEN
d1data <= d1data_in;
END IF ;
END PROCESS;

gets mapped to the following in the xnf file,

SYM, d1data_in_inff<1>, IFDX, LIBVER=2.0.0
PIN, Q, O, d1_in/d1data<1>
PIN, D, I, d1data_in<1>
PIN, C, I, clk27m_c
PIN, CE, I, VCC


Is there a way to get synplify to infer the IFD primitive (D-flop w/o
enable) instead of the IFDX without making the source vender specific
or hacking the xnf file?? Does
anyone know where I can get older versions of Syplicity synplify (pre
6.0)? Thanks for any info.

Ted

You can certainly hack the xnf. Here are some code snippets that should help:

Input FF

SYM, d1data_in_inff<1>, INFF
PIN, Q, O, d1_in/d1data<1>
PIN, D, I, d1data_in<1>
PIN, C, I, clk27m_c
END

Output flipflop

SYM, MODULE_TOP/SIGNAME1, OUTFF, INIT=R
PIN, C, I, CLK_NET
PIN, D, I, MODULE_TOP/INT_MSEL0_21
PIN, O, O, MSEL0_21
END

Output flipflop with tristate

SYM, MODULE_TOP/SIGNAME2, OUTFFT, INIT=S
PIN, C, I, CLK_NET
PIN, D, I, MODULE_TOP/INT_MSEL0_31
PIN, O, O, MSEL0_31
PIN, T, I, MODULE_TOP/MSEL0_OUT_REG/OE
END




Philip Freidin
Fliptronics