The Essentials Of Computer Organization And Architecture 4th Edition by Linda Null,Julia Lobur

Exercise 71

The PC ? PC + 1 microoperation is executed at the end of every fetch cycle (to prepare for the next instruction to be fetched). However, if we execute a Jump or a JumpI instruction, the PC overwrites the value in the PC with a new one, thus voiding out the microoperation that incremented the PC. Explain how the microprogram for MARIE might be modified to be more efficient in this regard.