Chip Selects (IO Multiplexing)

This is a scope capture of the strobe timing signals comming from U27.  This shows the order in which the gain settings and eq settings get applied to the attenuation control chips.  I was surprised at how long it took from the first strobe to the last to set the data.  I placed markers on the signals that show it takes about 50ms and that is before midi latency and other latencies are figured in.  In my design, i'm shooting for a patch change to be in the 5-10ms range from the time the midi message is recieved to the time all analog parameters are set.  As can be seen, first OD1 and OD2 are set, then all of the eq settings, and finally, the master gain. The Q labels on the scope capture correspond to the labels on U27 on the MP-1 processor schematic. 
Capture of strobes during a patch change from the front panel.