Toggleo, Toggleas, Toggleat A nifty way of doing a two-way handshake without worrying about levels and ulse widths is to use a toggle exchange protocol. This is illustrated in Figure 6. Block a Block B Toggle A-B Data A-B Clock domain a Clock Domain B Toggle B-A Data b-a Clock a Clock B FIGURE 6. Using Toggle Signals to Cross Clock Domains In this case, the signal from Block A to Block B that indicates the data(Data A- B)is valid is a transition of the signal Toggle A-B. This transition may be low-to- The Ten Commandments of Excellent DesignCrossing Clock Domains The Ten Commandments of Excellent Design 11 Toggleo, Toggleas, Toggleat A nifty way of doing a two-way handshake without worrying about levels and pulse widths is to use a toggle exchange protocol. This is illustrated in Figure 6. FIGURE 6. Using Toggle Signals to Cross Clock Domains In this case, the signal from Block A to Block B that indicates the data (Data A￾B) is valid is a transition of the signal Toggle A-B. This transition may be low-to￾Clock Domain A Clock A Clock Domain B Clock B Toggle A-B Toggle B-A Data A-B Data B-A Block A Block B