Hi All,
I'm Taichi Ishitain. I'd like to inform my CSR automation tool named 'RgGen'.
RgGen is a tool to generate RTL, UVM reg model and Markdown from human readable register map specification written in YAML, JSON, TOML, Ruby and Excel.
https://github.com/rggen/rggen
Recently, I've published VHDL writer plugin for RgGen. You can generate CSR modules written in VHDL automatically by using RgGen and this plugin.
https://github.com/rggen/rggen-vhdl
You can find sample register map and generated VHDL modules from following links.
- Register map
- Generated VHDL modules
Thank you for your attention
in.
in, then one could use mode constant.
https://gitlab.com/synthworks/VHDL_2019
I came across this oddity compiling my testbench today.
package gen_pkg is
generic ( W : natural );
constant CONST : natural := W;
end package gen_pkg;
entity name_clash is
end entity name_clash;
architecture clash of name_clash is
package pkg is new work.gen_pkg generic map( 8 );
use pkg.all;
begin
p: process
package pkg is new work.gen_pkg generic map( 9 );
use pkg.all;
begin
report to_string(CONST);
wait;
end process;
end architecture;With this code, I get the error that the reference to CONST is ambiguous as it can I see two packages where it is visible. The question is, I know I can get to pkg.CONST local to the process, but how could I get the reference to CONST in the package in the architecture?
( The double declaration in my code was an error, but it got me wondering )
p. but I'm not sure if it is p.pkg.CONST or just p.CONST because you used all.
PS C:\Temp> ghdl.exe -a --std=08 "C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl"
C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl:19:13:warning: declaration of "pkg" hides instantiation package "pkg" [-Whide]
package pkg is new work.gen_pkg generic map( 9 );
^
C:\msys64\home\Patrick Lehmann\temp\trickyhead.vhdl:22:22: no declaration for "const" (due to conflicts)
report to_string(CONST);
^
C:\msys64\mingw64\bin\ghdl.exe: compilation errorentity name_clash is
end entity name_clash;
architecture clash of name_clash is
constant CONST2 : bit := '0';
begin
p: process
constant CONST2 : bit := '0';
begin
report to_string(CONST2);
wait;
end process;
end architecture;The example above doesn't fail, because here, both constants have no conflict. The one in the process hides the other one.
GHDL reports a
-Whide warning, but no error.
Use behave differently.
"NOTE 1—These rules require that a declaration that is made directly visible by a use clause cannot hide an otherwise
directly visible declaration. Moreover, an explicitly declared operation has priority over an implicitly declared
homograph of that operation if both are made potentially visible by use clauses."
entity name_clash is
end entity name_clash;
architecture clash of name_clash is
begin
p: process
package pkg is new work.gen_pkg generic map( 9 );
use pkg.all;
begin
# report to_string(CONST);
wait;
end process;
process
begin
report to_string(CONST);
wait;
end process;
end architecture;But luckily it doesn't!
but you have no visible package to get
CONSTin the 2nd process?
I did an inverse proof. When the LRM says both Use Clauses can not hide each other, they must be in the same scope.
This means, the Use Clause is applied to the parent layer (here architecture). If it's applied to the Process, it would be a new scope and thus can not collide.
So if it's in the architecture layer, it should be visible in the 2nd process, right?
But it's not.
As you can see with normal constants above, the tools solves the problem for
CONST2
- In 87,
characteris defined over USASCII, socharacter'pos(character'right)is 127. - In 93:
characteris defined over ISO8859-1 socharacter'pos(character'right)is 255.
If we separately compile two architectures, one in 87 and one in 93 and elaborate them into a single design, what is expected?