P
parag_paul@hotmail.com
Guest
Is it meaning full to have local params in SV class
SV - System Verilog
SV - System Verilog
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J
Jonathan Bromley
Guest
On Wed, 10 Dec 2008 04:12:50 -0800 (PST), parag_paul wrote:
want to use a static const instead.
At least one simulator tolerates parameters and
localparams in classes. I can't really see what's
wrong with having them, but it's probably not very
helpful either.
Note that the simulator that does accept localparam
inside a class also accepts "parameter", but treats
it the same as "localparam" - in other words, you
can't override the parameter on instantiation. So:
class C #(parameter P = 5);
localparam L = 3;
parameter LP = 2;
endclass
C #(4) c = new; // parameter P = 4
C #(6, 7) d; // illegal, can't override LP
I have a vague feeling that the rules for this may
have slightly changed in the proposed 2009 standard,
but I'm not sure - I'll check some time soon.
--
Jonathan Bromley, Consultant
DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
jonathan.bromley@MYCOMPANY.com
http://www.MYCOMPANY.com
The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.
According to the LRM, it's illegal. You probablyIs it meaning full to have local params in SV class
want to use a static const instead.
At least one simulator tolerates parameters and
localparams in classes. I can't really see what's
wrong with having them, but it's probably not very
helpful either.
Note that the simulator that does accept localparam
inside a class also accepts "parameter", but treats
it the same as "localparam" - in other words, you
can't override the parameter on instantiation. So:
class C #(parameter P = 5);
localparam L = 3;
parameter LP = 2;
endclass
C #(4) c = new; // parameter P = 4
C #(6, 7) d; // illegal, can't override LP
I have a vague feeling that the rules for this may
have slightly changed in the proposed 2009 standard,
but I'm not sure - I'll check some time soon.
--
Jonathan Bromley, Consultant
DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
jonathan.bromley@MYCOMPANY.com
http://www.MYCOMPANY.com
The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.
J
Jonathan Bromley
Guest
On Sun, 14 Dec 2008 20:36:05 +0000, Jonathan Bromley wrote:
permits localparam and parameter inside a class.
In both cases you get a local parameter; if you
want to parameterize (template) the class, you
must put the corresponding parameter(s) in the
class declaration header.
This may be useful, because (as far as I understand)
parameters are constant expressions whereas
const variables are not.
--
Jonathan Bromley, Consultant
DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
jonathan.bromley@MYCOMPANY.com
http://www.MYCOMPANY.com
The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.
Indeed they have. The current draft of SV-2009Is it meaning full to have local params in SV class
According to the LRM, it's illegal. You probably
want to use a static const instead.
[...]
I have a vague feeling that the rules for this may
have slightly changed in the proposed 2009 standard,
permits localparam and parameter inside a class.
In both cases you get a local parameter; if you
want to parameterize (template) the class, you
must put the corresponding parameter(s) in the
class declaration header.
This may be useful, because (as far as I understand)
parameters are constant expressions whereas
const variables are not.
--
Jonathan Bromley, Consultant
DOULOS - Developing Design Know-how
VHDL * Verilog * SystemC * e * Perl * Tcl/Tk * Project Services
Doulos Ltd., 22 Market Place, Ringwood, BH24 1AW, UK
jonathan.bromley@MYCOMPANY.com
http://www.MYCOMPANY.com
The contents of this message may contain personal views which
are not the views of Doulos Ltd., unless specifically stated.