Reference no: EM133300772
1. You have been hired by a company to design a circuit to encrypt passwords. Assume passwords are 3 bits in size and that the encrypted password is the original password inverted (0's become 1's and 1's become 0's) and then add 3 (modulo 8 as we only have 3 bits). For example if the password is 000, we invert it to give us 111. We then add 3 (7 + 3 = 10 mod 8 = 2) which makes the encrypted password 010. Design and build a sequential circuit (using the procedure from your notes) using 3 T flip-flops to perform the above function. You need to show the State Table, K-maps and draw the sequential circuit.
2. Using D flip-flops, implement a 3-bit register with one external input (x). When the external input x = 0, the registers should rotate to the left by 1 bit, and when the external input x = 1, the value in the register should increase by 1. When creating your State Table, please put the flip-flop values before the external input (i.e., D2 D1 D0 x). See the example on Pages 14-17 of Module 4, Topic 3 (marks will be deducted if you use a different ordering in your State Table). You need to show the State Table, K-maps and draw the sequential circuit (see Pages 14-17 of Module 4, Topic 3).
3. Redo the Vending Machine Example from Module 5, Topic 1 (pp. 20-25) assuming that the cost of gum is 20 cents. Also, use T flip-flops instead of D flip-flops as was used in the example from the lecture notes. You need to show the State Diagram, State Table, K-maps and draw the sequential circuit.
4. Consider the following combinational circuits: (i) F1 (x,y,z) =Σ(1,2,5,6) F2 (x,y,z) = Σ(1,3) F3 (x,y,z) = Σ(0,4,7) (ii) F1 (w,x,y,z) = Σ(0,4,6,10,12,14) F2 (w,x,y,z) = Σ(2,3,4,8,11,15) F3 (w,x,y,z) = Σ(0,2,9,13) F4 (w,x,y,z) = Σ(10,11,14,15) a) Implement Part (i) using a ROM chip (be sure to specify the size). b) Implement Part (ii) using a ROM chip (be sure to specify the size). c) Implement Part (i) using a 16x4 ROM.
5. Consider a RAM chip with a capacity of 32M words of 8 bits each. a) How many address and data lines are required for this chip? b) How many 32M x 8 RAM chips would be required to construct an 128M x 16 RAM chip? c) How many address and data lines are required for an 128M x 16 RAM chip? d) What size decoder is needed to construct an 128M x 16 chip from 32M x 8 chips? e) Draw a diagram of the 128M x 16 chip built from 32M x 8 chips. Include the range of addresses for each chip.