The Alarm System

Goals
Instructions
Figures
1. Figure 3
2. Figure 4

With a working clock, you decide to make it an alarm clock. You think deeply about what are the major components of making an alarm work, and decided that there are two; setting the alarm and sounding the alarm.

With the ideas still fresh in your mind, you create the flowchart in Figure 3 that combines the setting logic of your clock alongside with the logic for setting the alarm functionality. You then also think about how to create a mechanism for the alarm to sound on the set time, and with that in mind you create another flowchart for you to use in Figure 4.

However, you are still stumped on how to store the alarm time, but your mentor comes back again to save the day by providing you a BabylonianAlarm component.

Goals

Learn how to use Digital
Add the following functionality to your clock:
- Setting the alarm time
- Sounding the alarm when the time has been reached

Instructions

All of your work should be in the same circuit from the previous section called ConventionalAlarmClock (it will save as ConventionalAlarmClock.dig).

Your task is to add alarm functionalities to your existing clock.

If you refer to the circuit structure, there are a couple of important inputs to keep in mind for this section:

ALARM_EN
SETUP_ALARM
MIN_ADV
HR_ADV

Setting Alarm Operation

The SETUP_TIME and SETUP_ALARM could be high at the same time. If this does happen, then your circuit should return back to normal operation (i.e. continue counting like normal).

To store the counters of the variable, you can use the BabylonianAlarm component.

During the setting time operation, the SETUP_ALARM signal will be high. While this signal is set high, the external clock input (CLK) should not modify the stored time in any way. During this operation, the advance signals (MIN_ADV or HR_ADV) can be set high. On rising edges of these signals (i.e. the signal goes from 0 to 1), then the corresponding counter storing the value for the alarm should be incremented by 1.

Example

Suppose the clock is at 00:00:54. Suppose that the alarm time set is 00:00:00. Suppose that we get the following input waveform:

CLK        : ⎽⎽/⎺⎺\⎽⎽/⎺⎺\⎽⎽/⎺⎺\⎽⎽
SETUP_TIME : ⎺⎺⎺⎺⎺\⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽⎽
SETUP_ALARM: ⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺⎺
MIN_ADV    : ⎽⎽/⎺⎺\⎽⎽/⎺⎺\⎽⎽/⎺⎺⎺⎺⎺
HR_ADV     : ⎽⎽⎽⎽⎽/⎺⎺\⎽⎽/⎺⎺⎺⎺⎺⎺⎺⎺

Then the final time the clock should display is 00:00:55 as both SETUP_TIME and SETUP_ALARM were high, which means that the clock reverted back to normal operation, and since one rising edge of the clock occurred, we increment the seconds by one. However, since we then set SETUP_TIME low, that means we are operating in the setup alarm mode.

The alarm value that should be stored is 02:02:00 as:

We ignore the first rising MIN_ADV since it is during when both SETUP_TIME and SETUP_ALARM are high.
We have 2 rising edges of MIN_ADV remaining.
We have 2 rising edges of HR_ADV remaining.

Please modify your previous logic to account for this new setting logic.

Displaying the Alarm

It would be beneficial for the user to see what the current saved alarm is while they are in the setup mode. So, while SETUP_ALARM is set high, you should display the ALARM_MINUTES and ALARM_HOURS values on the seven segment displays. Since the alarm we implement doesn’t support seconds, please display 0 for the seconds place. When SETUP_ALARM is low, then the SECONDS, MINUTES, and HOURS signals should be sent to the seven segment displays.

Please modify your display logic to account for this.

Buzzing the Alarm

The last key piece for making an alarm clock work is to provide a BUZZ signal so that the TickTok Audio Team can use it to play a song while waking the user up (based on their personal harvested data of course). During normal operation, whenever the MINUTES == ALARM_MINUTES and the HOURS == ALARM_HOURS and ALARM_EN == 0, then the BUZZ signal should be set high.

Please add the logic to handle this.

Figures

Figure 3

Setting the Alarm Clock

flowchart LR
    A{SETUP_TIME == 1?}
    A1{SETUP_ALARM == 1?}
    A2{SETUP_ALARM == 1?}
    B{MIN_ADV ⎽⎽/⎺⎺ ?}
    B1{MIN_ADV ⎽⎽/⎺⎺ ?}
    C["minutes = minutes + 1
       display(minutes)"]
    C1["alarm_minutes = alarm_minutes + 1
       display(alarm_minutes)"]
    D{HR_ADV ⎽⎽/⎺⎺ ?}
    D1{HR_ADV ⎽⎽/⎺⎺ ?}
    E["hours = hours + 1
       display(hours)"]
    E1["alarm_hours = alarm_hours + 1
       display(alarm_hours)"]

    A -->|No| A1
    A -->|Yes| A2

    subgraph alarm [setting alarm]
    A1 -->|Yes| B1 & D1
    A1 -->|No| G["Do Nothing"]
    B1 --> C1
    D1 --> E1
    end 

    subgraph time [setting time]
    A2 -->|No| B & D
    A2 -->|Yes| F["Not possible"]
    B -->|No| C
    D -->|No| E
    end

    time & alarm -->|After Operation| A

Figure 4