I don't need charlieplexing description. only multiplexing method in ICM7217 display output
MAXPAYNE , You need to understand what multiplexing is .I would quickly sum ups as , in a 7 segment display all the LEDs are named a,b,c,d,e,f,g for each digit say four "8888" . Now all the 'a' are connected in parallel wit 'a' and 'b' with 'b' and so on till 'g' . And they have common LED anodes (cathodes are also there) which supplies voltage to only one digit OK. This way if you want to display say 1234 , first you glow f,e pins(refer to ICM7217 page 9-22) of all the 4 digits , BUT supply the anode voltage to only the first digit ,wow you can see 1 written on the display. Since you also need 2 now you withdray connection from first digit anode and its alpha digits , and supply the logic a,b,g,e,d and this time supply connection to second digit anode and so on . This process is repeated with very fast speed and our eyes are not able to distinguish the on/off time generated by the multiplexing procedure.