What meaning of two '#'s in a to_signed function?

[fl]

Hi,

I see the following VHDL code:


in5_out1_re <= to_signed(2#0000000000#, 10);


What meaning of the two '#'s above?

Thanks

 

[KJ]

On Friday, May 22, 2015 at 9:55:59 AM UTC-4, fl wrote:

Hi,

I see the following VHDL code:


in5_out1_re <= to_signed(2#0000000000#, 10);


What meaning of the two '#'s above?

Thanks

VHDL allows you to specify a base for a numeric literal. So if you want the number 65535, you can specify it as
65535 -- Implicit base 10
10#65535# -- Explicit base 10
16#FFFF# -- Hex
8#177777# -- Octal
2#1111111111111111# -- Binary

The # symbol delimits the beginning and end of the numeric literal.

Kevin Jennings