# openlane

Siva Prasad

10/18/2021, 6:00 PM
Hi all, In my design I have 2 clock domains with the necessary ccd logic. I wish to use wishbone clock as one clock and an external clock from io pin as the other. I have defined the clocks in sdc . Do I need to set any other variable so that cts buffers and builds these 2 clock trees correctly?

Matthew Guthaus

10/18/2021, 6:03 PM
Short answer: openlane does not support 2 clocks. You would need to modify the scripts to support this.