vhdl syntax '#' maens??

[rourabpaul]

what does in mean in VHDL
constant MAX_EXP : INTEGER := 2#11111111#;
i dont know what '#' means

 

[ckshivaram]

these are based integers
these are literals of VHDL
e.g. Decimal integers: 1 42 153_1203
Based integers: 2#1_0010# 16#F001D#
Characters: ’0’ ’1’ ’X’
Strings: "101011" "XXXXXX"
Bit string literals: B"1001_0101" X"95"
mean "10010101"
Underscores added for readability are ignored

 

[TrickyDicky]

the # means based integer - so the number inside the ## is in the base specified outside

so 2#1111# is 15 in base 2
16#F# is 15 in base 16

So the MAX_EXP constant is 255 in binary.

 

[rourabpaul]

Thank u so much

 

[ckshivaram]

read this as reference
**broken link removed**