Design a six $($decimal$)$ digit stopwatch using a Nios $2$ coding language with start$/$resume$,$ stop, and reset control buttons. The functions for each of the input buttons are as follows:

$1.$ START$\_$RESUME$-$ This button is used to trigger $($start$)$ the counting on the stopwatch, from an initial state of $00$:$00$:$00.$ When this input is activated, the stopwatch advances every centi$-$second counting up and displaying the elapsed time from a minimum of $00$:$00$:$00$up to a maximum of $99$:$59$:$99(99$minutes, $59$seconds and $99$hundredths of a second$)$ and then looping back to $00$:$00$:$00.$ The counting process should continue running until any other input $($SET or RESET$)$ is activated. A second press of the START$\_$RESUME button should not affect the current clock $($time count$).$ If the START$\_$RESUME input is activated from a previous steady display on the stopwatch, then the stopwatch resumes counting from the displayed value.

$2.$ ET$-$ This button is used to stop the stopwatch counting and to hold the display. When this button is pressed the stopwatch stops counting at the very instance and displays the lap time $($in minutes$)$ continuously, until any other input $($RESUME or RESET$)$ is pressed. The difference between a regular pause of the stopwatch and using the lap time is that for the lap time, the stopwatch is still counting while displaying the lap time, even though the time displayed does not change. While the stopwatch is in SETmode there should be an $$L$$ displayed on HEX$0$

$3.$RESET$-$This button is used to reset the stopwatch display to $00$:$00$:$00.$ When this button is pressed, your stopwatch is reset to zero $($the display should read $00$:$00$:$00),$ irrespective of the state of your counter, and should hold this state until the START$\_$RESUMEbutton is activated. While the stopwatch is in RESETmode there should be an $$R$$ displayed on HEX$0.$

$4.$ GENERAL$-$ The current clock count MUST ALWAYS be displayed on the $18$ red LEDs LEDR$0-17.$ KEY$0$ MUST NOT be used because it is reserved for use as a reset mechanism for the DE$2-115$ Media Computer.

INPUT$-$OUTPUT INTERFACE

$1.$ Use the push buttons, KEY$1-3,$ and the $7-$segment display LEDs HEX$2-7,$ available on the DE$2-115$ board as indicated in TABLE $1$ below.

$2.$ How to Track Time? $-$ Use the $50$ MHz internal clock on the DE$2-115$ board as the reference for computing time. Hint: If I have a clock running at $50$ MHz$,$ how many clock cycles will I observe in $1/100$ second? The intellectual challenge here is to do the necessary $$clock division$$ within your NIOS$2$ assembly code to increment the counter every $1/100$ second.

Table $1$ describes the functionality of digits, push buttons and input$/$output devices on the stopwatch. Figure $1$ shows the stopwatch display from the top$-$level design.

TABLE $1$: Function$($s$)$ of digits, push buttons and IO Devices $-$ the table image is attach