micro programming

Question

consider  a micro programmed control unit each of which takes 16 micro operations.The system supports 16 flag conditions and 54 control signals .If horizontal microprogramming control is used then what is the length of control word(bits/word)?

Answer 1

the no. of bits in control word = no. of bits for flag + no. of bits for control signal + no.of bits for control memory

bits for flag = log2(16)

bits for control signal = 54 (for horizontal )

bits for control memory = log2(no. of instruction * no. of micro operation per instruction) = log2(total micro operations)= log2(16)= 4

therefore no. of bits in control word = 4+54+4=62

Comments

@Abhishekcs10  What if Vertical Programming is used in the question ?
Will there be any change in bits for control memory ?
 

---

There will be only change in control signal , i guess so

---

For vertical  programming the control signals are binary encoded .... so number of bits would be log2(54) i.e. 6 bits. Rest is same

---

I think the question is incomplete.

We are given with the number of microoperations per instructions but the number of instructions is not given.

Since, size of control memory = (No. of instructions * No. of micro operations per inst.)

Here No. of micro operations per instruction = 16

No of instructions = ???

Please let me know if I am missing something