shift register

[puka1012 (Gast)]

bit_out <=bit_out(30 downto 0) & '1';


kann jemand mir mit eine beispiele erklären was die oben zeile 
macht(besser waäre auf englisch).Danke

[Antti L. (xilant)]

its part of code for shift register

[puka1012 (Gast)]

can you please explain?

[Antti L. (xilant)]

you should look at the FULL code, then it can be explained too

[Falk B. (falk)]

bit_out <=bit_out(30 downto 0) & '1';

This is a simple signal assignemt. It takes the lower bits 30-0 of 
bit_out and concatenates it with the constant '1' at the lowest bit 
position. This is assigned to bit_out again. This is a logic shift left 
operation, which feeds a logic one into the LSB (least significant bit).
Another cumbersome way to describe it would be like this.

bit_out(31) <= bit_out(30);
bit_out(30) <= bit_out(29);
bit_out(29) <= bit_out(28);

...

bit_out(1) <= bit_out(0);
bit_out(0) <= '1';

[puka1012 (Gast)]

Thank you

[Lothar M. (Firma: Titel) (lkmiller) (Moderator)]

The & operator is the concatenation operator. It connects bits and/or 
vectors to a new vector.

It is not the AND operator as in C.