Table 24: Summary of special characters
String variables should be declared as reg type vectors (
Example
2
). Each character needs 8 bits.
If a string variable is used in an expression, it should be treated
as an unsigned value. If the size of a string assigned to a string
variable is smaller than the declared size of the variable, then it
will be left-padded with zeros.
The null string " should be treated same as "\0.
Concatenations of string variables preserve left-padded zeros of
these variables (
Example 3
).
Examples
Example 1
"\n This is the first line\n
This is the second line"
"\t Line\t with\t tab\t characters"
Example 2
reg
[8*12:1] message;
The message variable can contain 12 characters.
Example 3
reg
[10*8:1] s1, s2;
s1 = "Verilog";
s2 = "-HDL";
{s1, s2} <> {"Verilog", "-HDL"}
These expressions are not equal because {s1, s2} has 0s between
"Verilog and "-HDL and {"Verilog,
"-HDL} does not have any 0s between words.
Important Notes
Concatenation of string variables preserves left-padded zeros of
these variables.
