Question 1

Sydney International Airport has asked you to design a combinational circuit to control entry of future international arrivals once COVID-19 vaccinations become more widespread across the world. Based on their vaccination/health details, passengers are either sent to one of five NSW quarantine hotels or allowed to quarantine at home.

In the system, when a passenger disembarks from the plane, they are met by NSW Health personnel who check their temperature, their identification and their COVID-19 vaccination details in a Health check room (see block diagram on next page). Only one passenger is allowed in the room at a time. The health official validates the passenger’s details and provides them with a ticket with a magnetic strip to use at the readers that control their exit. At the room exit, the passenger enters the card provided into a reader (Reader 1). The reader will produce a 2-bit code for your circuit as follows:

Card code                A1 A0

No card inserted         0 0

Quarantine hotel         0 1

Al home quarantine 1 0

Invalid card                 1 1

If Reader 1 detects a code for a quarantine hotel, your circuit will generate an output to open Door 1, which takes the passenger to a waiting area for quarantine passengers (Area 1). In the waiting area, the passenger will enter their card into a reader (Reader 2) and Reader 2 will provide your circuit with a 3- bit code corresponding to one of five possible hotels that the passenger will quarantine in. Based on the code read and whether the Door 1 output was generated, one of the five doors for the bus taking them to the corresponding hotel will open. If none of the codes are read or Door 1 output was not received, an alarm is generated. The codes for the hotels are as follows:

Hotel code Hotel

001                 AMR

011                 WDX

100                 GFR

101                 STE

111                 ZCR

If the first card reader detects a code for at home quarantine, your circuit will generate an output to open Door 2, which takes the passenger to the terminal arrival area (Area 2). At the terminal exit, the passenger will need to enter their card into another reader (Reader 3). Reader 3 will provide your circuit with the 3-bit code 000. Based on the code read and whether the Door 2 output was generated, the terminal exit door will open. If the right code is not read or Door 2 output was not received, an alarm is generated.

The inputs to your circuit will be

• a 2-bit card code A[1:0]

• a 3-bit code B[2:0]

The outputs of your circuit will

• a single bit X controlling Door 1

• a single bit Y controlling Door 2

• a single bit Z for the alarm generated if either

o Reader 1 at the arrival area exit detects no card or an invalid card, or

o Reader 2 or 3 do not read a valid code for their respective areas (Area 1/2) or the Door output for their area (Doro 1/2) was not received.

• 6 bits W[5:0], where the most significant bit controls the terminal exit door for at home quarantine passengers and the remaining five bits control the doors for each of the five hotel buses in the order given above (i.e. W4 - AMR; W0 - ZCR).

You can choose the technology to implement the circuit with (AND/OR, NAND, multiplexers, etc.)