Computer Architecture 5.C Using Table 7-1, the microinsuction code format in Fig

ID: 665765 • Letter: C

Question

Computer Architecture 5.C

Using Table 7-1, the microinsuction code format in Fig. 7.6 and given the 20-bit microoperation field for the following microoperations: 96, INCDR, COM, NEXT 97, XOR, NEXT 98, READ, PCTAR,NEXT a- Convert the above microinstructions into RTL expressions. Control Memory Address | INCDR COM NEXT Control Memory Address |XOR NEXT O Control Memory Address | READ | PCTAR NEXT b- Write the 20 bit binary code for the above microoperations. Control Memory Address F1 F2F3 CD | BR | ADD C- Rearrange the order of the previous microoperations to achieve an XNOR operation between a value in the memory and a value in AC and repeat parts a and b. Control Memory Address | READ | PCTAR NEXT Control Memory Address | XOR NEXT Control Memory Address | INCDR COM NEXT Control Memory Address F1 F2 F3 | CD | BR | ADO

Explanation / Answer

b) 20 bit binary code

F1 - 110

000

101

F2 - 000

100

101

F3 - 000

101

000

CD - 00

BR - 00

AD - 1000001

1000010

0000000

a) INCDR - DR<----------DR+1

COM - AC<---------- AC'

XOR - AC<------- AC + DR

READ - DR<------- M[AR]

PCTAR - AR<------ PC

c) READ - DR <---------- M[AR]

PCTAR - AR <--------- PC

XOR - AC <-------- AC + DR

INCDR - DR <------ DR + 1

COM - AC <------AC'