Repeat Problem 10-21 for the CISC instruction, Memory Vector Add. This instruction uses the contents of R[SB] as the vector length. It adds the vector with its least signiicant element in memory pointed to by R[SA] to the vector with its least signiicant element in memory pointed to by R[DR]. The result of the addition replaces the vector with its least signiicant element pointed to by R[DR].

Problem 10-21

Write microcode for the execution part of each of the following CISC instructions. Give both a register transfer description and binary or hexadecimal representations similar to those shown in Table 10-6 for the binary code for each microinstruction.

Table 10-6

(a) Branch if overflow

(b) Branch if greater than zero

(c) Compare less than

(a) Push: R[SA] DR=SA. R[SA] + 1 followed by M[R[SA]] R[SB]. Assume (b) Pop: R[DR] M[R[SA]] followed by R[SA] R[SA] 1. Assume SB=SA.