EEL 3701C – Digit Logic & Computer Systems Homework 3 72 pts Problem I (Encoder, Decoder, 11pts) 1) Show how to make the 8-to-3 priority encoder representing the picture below using two 4-to-2 priority encoders and any additional necessary gates (5 pts) 2) Realize a full subtracter using a 3-to-8 line decoder with inverting outputs and a) two NAND gates (3 pts) b) two AND gates (3 pts) Problem II (Memory, 15 pts) 1. Using a graphic explain the following memory technology: mask-programmed ROM, PROM, EPROM, EEPROM, EEPROM, FLAS, RAM, SRAM, DRAM (9 pts) 2. Sketch the internal design of a 8 × 3 ROM with the following: value 2 is stored at address 1, value 5 store at address 5, value 1 store at address 0 and value 0 stored at all remaining addresses. (2 pts) 3. Compose 1kx8 ROM’s into an 8kx8 ROM (2 pts) 4. Show how to use a 1kx8 ROM to implement a 512×6 ROM (2 pts) Problem III (Arithmetic, 14 pts) 1. Use the shift and add algorithm to perform the following multiplications 15×66 (2 pts) (-55) x (-35) (3 pts
) 40 x (-16) (3 pts) 2. Use the restoring algorithm to perform the following divisions 58/13 (3 pts) 85/27 (3 pts) Problem IV (Microprogramming, 17 Pts) The circuit below counts the number of 1’s in an input A. Assume A is available when a start signal s becomes 1; A is loaded into a parallel loading shift register. At the same time a value is loaded into an up-counter C. After completing the count of 1’s, the controller generates a signal Done until s has returned to 0. (Note that the serial input to R, ai, can be a constant value.) For the shift register: For a right shift Sh = 1, Ld = 0 or Ld = 1. For a left shift, Sh = 0 , Ld = 1 For the counter: Load Ld = 1, IncC = 1 count up 1) Specify the value to be loaded into C (2 Pts). 2) Design the controller as microprogrammed unit (15 Pts). Problem V (Assembler Programing with SPIM, 15 Pts) Use the SPIM simulator to compile and run your assembler program of Exercise 5. A guide for executing and debugging programs in the SPIM environment is provided on canvas.