ECO gates can be inserted into connections between gates. For example the following
n588 net (in red) can be inserted several ECO
gates. Select the connection by clicking Mouse-Left-Button on it. Press 'Insert
gates into connections' button.
Type in the gate number to be inserted.
In ECO Gate select window, select INVX2
Select complete Loop since the gate is inserted into the connection
Two INVX2 are inserted as following. The gate positions can be adjusted any
time for readability
You can add other type of gate which has more than one inputs. For example AND cell.
In Connectivity selection window, Y and A are default set to 'Complete Loop', B's default is 'Undriven'. You can choose 'Driven by' option. And in the entry, type in the net name.
Or use fast way, click Mouse-Left-Button in the entry to activate it,
click Mouse-Left-Button on the net that should drive B, n256 in this case.
AND2X4 is inserted with the connections specified above.
Use Mouse-Right-button to get popup menu and select 'Edit gate'. Change instance name and add some comments.
The instance is changed and comments are added as the following figure shown.
Save ECO. And check ECO. Tcl format is listed below.
