Suppose the control memory in fig 7-2 has 4096 words of 32 bits each. The microinstruction has three fields as shown in the diagram. The microoperations field has 12 bits.

a) How many bits are there in the branch address field and the select field?

b) If there are 16 status bits in the system, how many bits of the branch logic are used to select status bit?

c) How many bits are left to select an input for the multiplexer.

Explain each question

218 CHAPTER SEVEN Microprogrammed Control Instruction code Mapping logic Status Branch MUX bits logic Multiplexers seiect Subeoutine register (SBR) Conrol address register (CAR) Clock Incrementer Comrol memory Select a status bit Microoperatiors Branch address Figure 7-2 Selection of addres for control memoey.