Re: pragmas

Eli Sternheim (eli@interhdl.interhdl.com)
19 Jul 1998 15:18:39 -0000

Is there any formal description of where exactly in the source code
the pargmas have to appear? For example in the "case" pragmas, do they
have to be on the same line that the keyword "case" is? do they have
to come after the "case" or before the "case"? etc.

Eli

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From: "Smith, Douglas J" <djsmith@ingr.com>
Date: Fri, 3 Jul 1998 14:10:24 -0500
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All,

At the recent face-to-face meeting we discussed pragmas. One of
the issues was a means of communicating to a synthesis tool that
it should map directly to a multiplexer. As such I have am proposing

// rtl_map_to_mux

which can be associated with a case or if statement.
The problem I see with this is that it could excalate, for example,
why not hae a pragma for mapping onto a counter.
Please send in and feedback. When I send out email to this reflector
I will include at the bottom a full list of proposed prgmas as they
exist at that point in time. Currently this is as follows.

Doug Smith

Verilog IEEE 1364.1 - proposed pragmas
======================================

The following pragmas are being proposed for the standard:

1. Conditional compilation pragmas

// rtl_synthesis off
// rtl_synthesis on

2. Case decoding pragmas

// rtl_full_case
// communicates to the synthesis tool case choices are exhaustive.

// rtl_parallel_case
// communicates to the synthesis tool case choices are mutually
exclusive.

3. Mapping to a multiplexer

// map_to_mux
// communicates to the synthesis tool to map directly to a
multiplexer
// and shall apply to case and if statements.

-- 
Eli Sternheim                          interHDL, Inc.
4984 El Camino Real, Suite 210         Los Altos, CA. 94022-1433
phone: 650-428-4200                    fax:   650-428-4201
email: eli@interhdl.com
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