Design requirement. Wish to replace some hardware logic to miniaturize a circuit. Would be great to be able to do this in the Propeller as we have some COGS left and also I/O pins We probably could spare 4 to 6 maximum I/O lines if hardwired interconnects between COGS is needed ( would not mind this as speed and performance is what is needed) See the attached PDF schematic of the circuit. Brief explanation. There are 2 signals that are considered inputs from external devices. There is one output on the right of the schematic (from the 3 input AND GATE). Once we get the below shorted we could possibly look at also using the Propeller to do another tricky timing thing as well... Input labelled "CAM" is a signal from a high speed sensor that comes from a timing cam inside a machine. The signal is on 28 mSec (0.028 secs) and is off for 28 mSec (0.028 secs) Input labelled "Enable" is really a GO signal from an external PLC that tells the Propeller to do its task ( The propeller also does one other task not relevant to this issue but the signal is there) What needs to happen is the following. #1 As soon as the "ENABLE" input goes high together with the "CAM" signal when it is low will send the FLIP FLOP Q high This is the main objective ie to sync the first pulse from the CAM sensor correctly .. So if the "ENABLE comes on while the CAM is on ie ' HIGH' it is to be ignored .. we need to see a low first from the CAM. #2 The Enable stay's high and the "CAM input " now every time it goes high can go thru the final 3 INPUT AND GATE. Remember the cam signal cycles at 28 msec on and 28 msec off .... So the final signal from the 3 input AND GATE reflects the ENABLE being high + the CAM signal being HIGH. As you can see the ENABLE resets the FLIP FLOP and also is connected to the final 3 input AND GATE as it is of paramount importance that no signal goes thru the final stage when the "ENABLE" is LOW www.nollet.com.au contact Ronald Nollet email : ron@nollet.com.au