Networking is advancing at a very high rate. Structured Hardware Design A new scanner for small objects consists of a transmitting array of 512512 elements and a receiving array of similar size. Each array is 4 cm on a side and the two arrays are placed 4 cm apart so that a total volume of 43 cubic centimetres can be scanned. Each transmitting element has two inputs that may be directly connected to digital logic and which are internally ANDed by the element. The scanner operates in still image mode by delivering a complex pattern of microsecond resolution pulses to the transmitting array over the course of one millisecond. The more pulses that can be delivered, the better quality the image. The complete pattern of pulses is determined in advance by software. The software will be aware of any constraints you may implement in the hardware that generates the pulses. Please execute the following steps in the design of the transmitter array: (a) Design and sketch out the inter-wiring between the control electronics and the transmit array elements. Hence decide how many custom chips (integrated circuits) to use, taking into account a 100 pin limit for each chip. [8 marks] (b) Decide how much RAM is needed on each chip to store the pattern and explain the data representation in RAM you have selected. Justify your decision. [4 marks] (c) Show how the transmitting and receiving arrays may both be wired into the address space of a controlling microprocessor. [4 marks] (d) Sketch out the internal architecture of each transmitter chip, showing the major blocks.

(a) Name at least four different types of ethical theory. [4 marks] (b) You are building a flight-control system for which a convincing safety case must be made. Would you assign the tasks of safety requirements engineering, test case development and assurance documentation to a separate team, or distribute them among your developers? Justify your answer briefly. [4 marks] (c) Describe two particular features of ML and two (different) features of Java that might be expected to help the process of designing, implementing, debugging or maintaining high quality programs in a cost effective manner. Explain whether the features you have noted are ones that come into play for all users or if they are capabilities that a user can choose to use or to ignore. [4 marks] (d) Draw a state diagram for a deterministic finite automaton that accepts w {a, b} if, and only if, w either begins with a and is of odd length or begins with b and is of even length. [4 marks] (e) A (ROM) Read Only Memory has 8 address inputs and 8 data outputs. Estimate how many two-input gates would be required, on average, to perform the function of the ROM. [4 marks] 2 CST.2004.2.3 SECTION B 2 Digital Electronics The functionality of a 2-to-4 line decoder is presented in the table below. inputs outputs A1 A0 EN S3 S2 S1 S0 X X 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 0 0 1 0 1 0 1 0 1 0 0 1 1 1 1 0 0 0 (a) What are the minimum sum-of-products equations for each output of the 2-to-4 line decoder? [4 marks] (b) How can five 2-to-4 line decoders be used to produce a 4-to-16 line decoder? Illustrate your answer using a circuit diagram. [6 marks] (c) An LED is to be controlled via a CMOS inverter. When the input to the inverter is 1, the LED should illuminate. The on current should not exceed 20mA at which point the voltage drop across the LED will be 1.5V. What circuit should be used to control the LED? Please include resistor values. [4 marks] (d) You have been asked to design the output interface for a novelty clock which represents time using just 12 LEDs. The LEDs are arranged in a circle to represent the hours on an analogue clock. You have been provided with a time-keeping component which produces a 2Hz signal and two 4 bit outputs H and M representing hours and minutes, where H = h mod 12 M = m div 5 h = hours (in the range 1 to 12) m = minutes (in the range 0 to 59) The LED which represents the minute is to flash at 1Hz whereas the hour LED does not flash. If the same LED is being used for both the hour and minute, it should flash. Produce a circuit diagram which meets this specification, making good use of the 4-to-16 decoder parts. [6 marks