Q4. In order to re-open after the COVID-19 shutdown, small shops and groceries with no more than 4 aisles are required to: only allow customers to enter or exit their store, one at a time, direct customers within the store so that there is one-way traffic in any given aisle, restrict the number of customers inside the store to 50 or less Your team has been asked to design an FPGA-based controller for a "Crowd Con- trol System to help proprietors and operators of small shops and groceries adhere to COVID-19 crowd-control guidelines, by allowing them to monitor the number of persons, and their direction of movement, within their premises at any given time. In addition to the FPGA controller, the system will consist of a 12-key non-matrix keypad, multiple buzzers, and multiple non-contact proximity sensors, with appropriate circuitry to connect these items to the controller. Your team has generated a behavioural description (see Figure Q4) which will be implemented by your team using the FSM+D design process. (a) Differentiate between the following phases of the FSM+D structured design pro- cess: FSM-D interface definition; Data-path interface definition; and Control-path (FSM) interface definition. What is the benefit, or drawback, to defining the three interfaces separately, as opposed to at-once? Your answer should make specific reference to the "Crowd Control System". 6 marks (b) Design a data-path for the Crowd Control System using appropriate modules. 6 marks (e) Design a single finite-state machine to control the data-path from Q4.b. 8 marks (d) i. How will the controller for the "Crowd Control System respond if spurious signals, due to faulty wiring, are generated by the proximity sensors at entry, exit and aisle? Your answer should consider whether the behavioural descrip- tion (see Figure Q4) and your designed data-path (see Q4.b) and control-path (see Q4.c) are fit-for-purpose, and make appropriate suggestions for revision. 8 marks ii. The maximum number of customers and aisles must be increased to 300 and 16 respectively. Identify any additional components, data-path elements, or changes to the specification or FSM controller, that would be required. Based on your observations, comment on the benefits/disadvantages of following the FSM+D design process. 8 marks Figure Q4: Behavioural Description of a Crowd Control System The clock signal driving the system will oscillate at 16kHz. A buzzer will sound when the corresponding signal is logic_low and stop when the corresponding signal is logic_high. Buzzer signals are BUZZER.0 to BUZZER-5, where BUZZER O is at the entrance, BUZZER_5 is at the exit, and BUZZER 1 (where r = 1 to 4) is at the entrance to Aisle r. A proximity sensor will output the following 2-bit pattern each clock cycle: - 00 - no person detected - 01 - person passed the proximity sensor in the forward direction within the clock cycle - 10 - person passed the proximity sensor in the reverse direction within the clock cycle 11 - person in front of the proximity sensor during the clock cycle Proximity sensor signals are PROXIMITY 0 at the entrance, PROXIMITY_5 at the exit and PROX- IMITY_r where r = 1 to 4 is at the entrance to Aisle r. The number of aisles within the store is a. This value can be changed when the system is in "pro- gramming" mode. When the system is in "operating mode": - The number of persons inside the store c is output via an 8-bit data-bus (COUNT) as an 8 bit unsigned binary number. - The value of c is adjusted based on persons observed passing the entrance (PROXIMITY_O) and exit (PROXIMITY_5). - When a person is observed moving in the wrong direction at the entrance, exit, or at any VALID aisle proximity sensor (i.e. the proximity sensor identifier 50), all buzzers will buzz continuously, until an appropriate number of persons remain in the store (e 50), all buzzers will buzz continuously, until an appropriate number of persons remain in the store (e
