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Design Languages >> VHDL-AMS >> Hamster vhdl-ams Error : Statement is not unique
https://designers-guide.org/forum/YaBB.pl?num=1501001349

Message started by loumbut5 on Jul 25^th, 2017, 9:49am

Title: Hamster vhdl-ams Error : Statement is not unique
Post by loumbut5 on Jul 25^th, 2017, 9:49am

Hi, the following code is generating the error: :'(

library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_unsigned.all;
entity program_counter is
port (
clk, en_A, ld, inc, reset: in STD_LOGIC;
aBus: out STD_LOGIC_VECTOR(15 downto 0);
dBus: in STD_LOGIC_VECTOR(15 downto 0)
);
end program_counter;
architecture pcArch of program_counter is
signal pcReg : STD_LOGIC_VECTOR(15 downto 0);
begin
process(clk) begin
if clk'event and clk = '1' then
if reset = '1' then
pcReg <= x"0000";
elsif ld = '1' then
pcReg <= dBus;
elsif inc = '1' then
pcReg <= pcReg + x"0001";
end if;
end if;
end process;
aBus <= pcReg when en_A = '1' else "ZZZZZZZZZZZZZZZZ";
end pcArch;

Specifically on the line:

pcReg <= pcReg + x"0001";

The error is:

(ARCHITECTURE pcarch OF ENTITY program_counter) : Error : Type mismatch

Please help with a fix. :)

Title: Re: Hamster vhdl-ams Error : Statement is not unique
Post by Geoffrey_Coram on Aug 7^th, 2017, 6:45am

I think VHDL is case-sensitive, so perhaps it should be
X"0000"
instead of
x"0000"

Title: Re: Hamster vhdl-ams Error : Statement is not unique
Post by Andrew Beckett on Aug 8^th, 2017, 1:33am

I don't think so Geoffrey - VHDL is a case insensitive language... I just checked in a book I have and it says "The base specifier can be in uppercase or lowercase".

Note that the module above when compiled in ncvhdl gives:

ncvhdl: 15.20-s028: (c) Copyright 1995-2017 Cadence Design Systems, Inc.
pcReg <= x"0000";
|
ncvhdl_p: *E,EXPTYP (forum2.vhd,17|34): expecting an expression of type STD_LOGIC_VECTOR 87[8.3] 93[8.4].
pcReg <= pcReg + x"0001";
|
ncvhdl_p: *E,BITOPR (forum2.vhd,21|26): This feature is allowed only in 93[13.7].

However, if I compile with -v93 or -v200x then it compiles with no problem.

Regards,

Andrew.