CS/ECE 252 Introduction to Computer Engineering
Spring 2020
Instructor: Adil Ibrahim
Project I: The WISC-SC252 Processor
3. JC, JA, JE, and JZ are a group of instructions in the J-format family. They are based on the four
flags C, A, E, and Z, and each plays a role in changing the execution sequence of a program. For
each of these instructions, the address to jump to is stored in the next memory location (e.g. if
a JC instruction appears at address 3, then address 4 contains the address to jump to). AND
gate number 101 in Figure 5 corresponds to the instruction that uses these flags.
Answer the following questions:
(a) What is the format of the Jump instruction in Figure 5?
(b) In the WISC-SC252 processor, it is possible to test more than one flag bit with a single
instruction. What is the maximum number of jump instructions we can have using the
four flags?
(c) Draw the logic diagram that selects among the instructions JC, JA, JE, and JZ
(corresponding to the FLAGS LOGIC box in Figure 5).
4. Answer the following questions:
(a) What is the maximum number of instructions the WISC-CS252 processor can support?
(b) What is the maximum memory size (in bytes) the WISC-CS252 processor can support?
(c) What is the addressability of the WISC-CS252 memory?