If this module were synthesised to the minimum sum of products form, what would the equations be for next state bits s[0], s[1] and s[2]? [6 marks] (b) ALGOL 60 provided call by value and call by name, Pascal provided call by value and call by reference, and ALGOL-W provided a variety of calling methods including call by result and call by value-result. [8 marks] 5 [TURN OVER CST.2004.13.6 6 Compiler Construction (a) Explain the differences (illustrating each with a small program) between (i) static and dynamic binding (scoping); [4 marks] (ii) static and dynamic typing. [2 marks] (b) Java is sometimes said to be "dynamically typed" in that a variable whose type is (class) C can be assigned a value of (class) D provided that D extends C; conversely a variable of type D can be assigned a value of type C using a cast. By considering storage layouts, explain why the former assignment is always valid and the latter sometimes invalid. [2 marks] (Use the next available subnet) Network R (LAN) requires 4 Usable host IP addresses. (Use the next available subnet) Network X (WAN) requires 2 Usable host IP addresses. (Use the next available subnet) Network Y (WAN) requires 2 Usable host IP addresses. (Use the next available subnet) Network Z (WAN) requires 2 Usable host IP addresses. (Use the next available subnet) Subnet Table: Subnet Description Network Address First Host Address Second Host Address Last Host Address Broadcast Address Subnet Mask Network P Network Network R Network X NA Network Y NA Network Z NA Part 2 The core relational algebra can be extended with a duplicate elimination operator, and a grouping operator. (i) Define carefully these two operators. [3 marks] 2 Hosts 50/1/1 S0/1/0 R11 R22 GOM S2 PC2 GO11 50/1/1 NW:10.10.100.0/24 50/170 Network P: 15 Hosts Network Q: 10 Hosts Network Z: 2 Hosts Network Y: 2 Hosts 50/110 50/1/1 R3 G0/1 Network R: 4 Hosts 53 PC3 Part 1: Design the VLSM Address Scheme Divide the 10.10.100.0/24 network based on the number of hosts per subnet and complete the Subnet Table. You will subnet the network address 10.10.100.0/24. The network has the following requirements: Network P (LAN) requires 15 Usable host IP addresses. (Use the third available subnet) Network Q (LAN) requires 10 Usable host IP addresses. [4 marks] (b) Describe an algorithm (other than thresholding) which will convert a greyscale image (8 bits per pixel) to a bi-level black and white image (1 bit per pixel), with the same number of pixels, while retaining as much detail as possible. [8 marks] (c) Explain what specular and diffuse reflection are in the real world. State and explain equations for calculating approximations to both in a computer. [12 marks] (b) [8 marks] Briefly describe the calling mechanisms just mentioned and discuss why most modern programming languages provide only call by value. [8 marks] . [6 marks] 3 [TURN OVER CST.2004.3.4 5 Operating Systems II (a) What problem do real-time scheduling algorithms try to solve? [2 marks] (b) If Reach is NP-complete then P=NP. [3 marks] (ii) If Reach is NP-complete then NP6=PSPACE. [3 marks] (iii) If Sat is PSPACE-complete then NP=PSPACE. (f ) Summarize any issues connected with left-or right-cooperative administrators in the two methods (in executing the parser and in developing the apparatus) you illustrated to some degree (e). (Use the next available subnet) module mystery(c,r,a,s); input c,r,a; output [2:0] s; reg [2:0] s; always @(posedge c or posedge r) if(r) s<=0; else begin if(a && (s<7)) s<=s+1; else if(!a && (s>0)) s<=s-1; end endmodule (a) How many flip-flops will be required to implement the mystery module, and how will signals c and r be connected to these flip-flops? [5 marks] (b) What is the state transition diagram for this mystery module? [5 marks]