usually these cells have properties that are better for a clock tree, with balanced fall and rise times. they are still perfectly valid cells to be used anywhere else in your design
usually these cells have properties that are better for a clock tree, with balanced fall and rise times. they are still perfectly valid cells to be used anywhere else in your design
The clock standard cells will have balanced rise times and fall times, but this is not the only benefit of these cells. The clock buffers I have seen use more silicon area and have the transistors spaced farther apart to help to minimize hot spots. The clock signals will toggle more often than the logic signals and require a more robust layout to handle the extra current.