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View Full Version : Is it possible to impliment Blockram with a reset?


RaymondCaleatry
07-27-2004, 04:40 PM
I am using the Xilinx webpack software, and have implimented a basic single
port blockram, however, if i try to add any reset functionality, the
Xilinx webpack synthesizer complains that it is no longer block ram. Is
there any way to reset block ram to pre-deturmined settings.

Raymond
----------------------------------------------
process (PCI_CLK)
begin
if (PCI_CLK'event and PCI_CLK = '1') then
if (we = '1') then
CONFIG_SPACE(conv_integer(a)) <= di;
end if;
read_a <= a;
end if;
end process;

spo <= CONFIG_SPACE(conv_integer(read_a));

end syn;

Tim Hubberstey
07-27-2004, 05:08 PM
RaymondCaleatry wrote:
> I am using the Xilinx webpack software, and have implimented a basic single
> port blockram, however, if i try to add any reset functionality, the
> Xilinx webpack synthesizer complains that it is no longer block ram. Is
> there any way to reset block ram to pre-deturmined settings.

No. It is possible to specify what values the RAM will contain when it
comes out of configuration but it is not possible to reset the RAM once
the device is in normal operation. This is done either with attributes
in your VHDL or with "INIT" statements in your .UCF file. See the Xilinx
documentation for details.
--
Tim Hubberstey, P.Eng. . . . . . Hardware/Software Consulting Engineer
Marmot Engineering . . . . . . . VHDL, ASICs, FPGAs, embedded systems
Vancouver, BC, Canada . . . . . . . . . . . http://www.marmot-eng.com