It uses a Ripple Counter made from DSR flip-flops to count each character from UCHILE-FCFM- and displays it into the 7-segment display, the logic behind was optimized using the Quine McCluskey algorithm.
You can test the desing by stepping the clock to see UCHILE-FCFM- in the 7-segment display. Also you can disable the counter with the 3th input and input a counter value by hand using the 4th to 7th inputs.
|4||A (most significant bit of the counter)||segment e||none|
|7||D (least significant bit of the counter)||dot||none|