Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

design mistake "sequential type is unconnected in block"

Status
Not open for further replies.

eng.fedail

Junior Member level 1
Joined
Aug 15, 2009
Messages
18
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
BXL
Activity points
1,389
In my design I'm assigning an output of block to a FF before feed it back to next block. it's working ok with me with the data vector but with a single variable is not working, I have tried to implement it in different case and I do still have the same problem

here is how I'm defining my instances

Code:
ALU1: entity work.CC_1 port map(S(11),S(10),Cin,S(9 downto 8),A,B,oTemp1,ocTemp(0));
ALU2: entity work.CC_1 port map(S(7),S(6),iTemp1(4),S(5 downto 4),iTemp1(3 downto 0),C,oTemp2,ocTemp(1));
ALU3: entity work.CC_1 port map(S(3),S(2),iTemp2(4),S(1 downto 0),iTemp2(3 downto 0),D,oTemp3,ocTemp(2));
and here is the loop when I assign the data and the signals

Code:
for i in 0 to 2 loop
	case i is
	when 0 =>
		iTemp1(3 downto 0) <= oTemp1;
		iTemp1(4) <= ocTemp(0);
	when 1 =>
		iTemp2(3 downto 0) <= oTemp2;
		iTemp2(4) <= ocTemp(1);
	when 2 =>
		Dout <= otemp3;
		Cout <= ocTemp(2);
	when others => null;
		end case;
end loop;
the errors are


WARNING:Xst:2677 - Node <iTemp2_4> of sequential type is unconnected in block <Pipeline>.
WARNING:Xst:2677 - Node <iTemp1_4> of sequential type is unconnected in block <Pipeline>.
WARNING:Xst:2677 - Node <iTemp1_4> of sequential type is unconnected in block <Pipeline>.
WARNING:Xst:2677 - Node <iTemp2_4> of sequential type is unconnected in block <Pipeline>.
 
Last edited:

FvM

Super Moderator
Staff member
Joined
Jan 22, 2008
Messages
47,447
Helped
14,039
Reputation
28,331
Reaction score
12,690
Trophy points
1,393
Location
Bochum, Germany
Activity points
275,962
Some more snippets would help to understand the problem.
 

eng.fedail

Junior Member level 1
Joined
Aug 15, 2009
Messages
18
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Location
BXL
Activity points
1,389
I got rid of all the warning messages by re-configuring the instance structure. but still in RTL cout is not connected as expected
attached is a snap Capture.PNG

updated code is

Code:
ALU1: entity work.CC_1 port map(S(11),S(10),Cin,S(9 downto 8),A,B,oTemp1,ocTemp1);
ALU2: entity work.CC_1 port map(S(7),S(6),iTemp1(4),S(5 downto 4),iTemp1(3 downto 0),C,oTemp2,ocTemp2);
ALU3: entity work.CC_1 port map(S(3),S(2),iTemp2(4),S(1 downto 0),iTemp2(3 downto 0),D,oTemp3,ocTemp3);
Code:
for i in 0 to 2 loop
				case i is
					when 0 =>
						iTemp1 <= ocTemp1 & oTemp1;
					when 1 =>
						iTemp2 <= ocTemp2 & oTemp2;
					when 2 =>
						Dout <= otemp3;
						Cout <= ocTemp3;
					when others => null;
					end case;
			end loop;
 

std_match

Advanced Member level 4
Joined
Jul 9, 2010
Messages
1,163
Helped
441
Reputation
882
Reaction score
407
Trophy points
1,363
Location
Sweden
Activity points
8,927
I am not sure what you are trying to do.
Your "for" loop is completely meaningless since you don't use "i" in it. The statements in the loop will have the same effect if you remove the loop and the null statement.

One advice, don't use positional port mapping. Sooner or later you will get the connections wrong and spend a lot of time debugging it. Use named port mapping and put only one port per line.
 

fouwad

Full Member level 4
Joined
Nov 29, 2009
Messages
197
Helped
19
Reputation
38
Reaction score
17
Trophy points
1,298
Location
Pakistan
Activity points
2,447
This kind of warning occurs when you donot use your register anywhere, or your condition never reaches the assigned register
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top