ANSWERS TO TOY EXERCISES


 1. R1 = 0001,  R2 = 0010

 2. R1 = 00FF,  R2 = 9111

 3. R1 = 0040,  R2 = 0000

 4. R1 = 0014,  R2 = 0001

 5. Need 11 bits to address the 2^11 = 2048 words, so "load" and "store" 
    instructions (for example)  have to be redesigned, since they need 
    4 bits for the opcode, 3 bits for the register, and 11 bits for the 
    address, 2 bits too many to fit into a 16-bit word.