Subject: Re: synthesis attribute question
From: Shalom Bresticker (Shalom.Bresticker@motorola.com)
Date: Sun Jul 07 2002 - 08:05:26 PDT
All of these will be illegal as 'conststring' is a variable (vector reg), not a
constant.
An attribute value must be calculatable at elaboration time.
Shalom
Muzaffer Kal wrote:
> hi,
> I think at least some of these should work but I am sure; given example 23
> on page 13 of the 1364.1 draft, are these valid per 1364-2001 + 1364.1-2002:
>
> 1)
> reg [8*13:1] conststring;
> initial conststring = "ROM_CELLXYZ01";
> ...
> (* synthesis, rom_block = conststring *)
> ...
>
> 2)
> parameter [7:0] n = "1";
> reg [8*12:1] conststring;
> initial
> begin
> conststring = "ROM_CELLXYZ0";
> end
>
> ...
> (* synthesis, rom_block = {conststring, n} *)
> ...
>
> 3)
> genvar i;
> reg [8*12:1] conststring;
> initial
> begin
> conststring = "ROM_CELLXYZ0";
> end
>
> ...
> generate
> for (i=0; i<8; i = i+1)
> begin:multiple_rom_blocks
> ...
> (* synthesis, rom_block = {conststring, i+8'h40} *)
> ...
> end
> endgenerate
> ...
>
> thanks,
>
> Muzaffer Kal
> DSPIA Inc. 408.654.9573
> http://www.dspia.com
> ASIC/FPGA design/verification consulting specializing in DSP algorithm
> implementations
-- Shalom Bresticker Shalom.Bresticker@motorola.com Design & Reuse Methodology Tel: +972 9 9522268 Motorola Semiconductor Israel, Ltd. Fax: +972 9 9522890 POB 2208, Herzlia 46120, ISRAEL Cell: +972 50 441478"The devil is in the details."
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