Select this option to enable the fitter to use local feedback path in XC9500 designs whenever possible. The local feedback path (from a macrocell-output to an input of the same function block) takes less time than the global feedback path. Using local feedback can speed up your design but can also make it difficult to keep the same timing after a design change.
To take maximum advantage of local feedback, control the placement to group appropriate signals into the same function block. In order to fit a design, the software may require wire-ANDing in the interconnect which can prevent local feedback use. However, you can force a local feedback by applying a tight timespec and assigning the signals to the same function block. This method prevents wire-ANDing of local feedback signal. The fitter generally uses the local feedback path whenever it is reuiqred to meet a tight timespec, regardless of the setting of this Use Local Macrocell Feedback option. By default, this option is on in the Balanced, Speed and User-customized templates, and off in the Density template.
Note: This option is available only in the XC9500 family.
The XC9536 device does not have local feedback.