Allocation of bits among opcode and operand, Computer Engineering

Assignment Help:

Allocation of Bits among Opcode and Operand

The trade-off here is between numbers of bits of opcode vs. the addressing capabilities. An interesting development in this regard is development of variable length opcode. 

A number of the factors which are considered for selection of addressing bits:

  • Number of addressing modes: The more are the explicit addressing modes more bits are required for mode selection. Though some machines have implicit modes of addressing.
  • As far as memory references are concerned granularity suggests whether an address is referencing a byte or a word at a time. This is more relevant for machines that have 16 bits, 32 bits and so on higher bit words. Byte addressing though may be better for character manipulation, butneed more bits in an address. For illustration memory of 4K words (1 word = 16 bit) is to be addressed directly then it needs:

WORD Addressing   = 4K words

                           = 212words

                        ⇒ 12 bits are needed for word addressing.

 

Byte Addressing    = 212 words

                          = 213 bytes

                        ⇒ 13 bits are needed for byte addressing.


Related Discussions:- Allocation of bits among opcode and operand

Explain the different page replacement policies, Explain the different page...

Explain the different page replacement policies. Various page replacement algorithms are briefly explained below: 1. First-in, first-out FIFO page replacement algorith

Draw back of assigning one bit position to control signals, What is the dra...

What is the draw back of assigning one bit position to each control signals? Assigning individual bits to every control signal results in long microinstructions due to the numb

Dbms, types of lock

types of lock

Explain instruction level of parallel processing, Instruction Level It ...

Instruction Level It refers to condition where different instructions of a program are implemented by different processing elements. Most processors have various execution unit

How do you make an append query, Append query can be used if you would like...

Append query can be used if you would like to add new rows of data to an already active table. The process of making an append query follows these steps they are. ? Basic step

Name some popular storage devices, Name some popular storage devices In...

Name some popular storage devices In contrasts with storage, which 1) retains data and programs irrespective of whether they are currently in use or not, (2) retains data

Unification algorithm - artificial intelligence, Unification Algorithm - Ar...

Unification Algorithm - Artificial intelligence: To merge two statements, we should get a substitution which forms the two sentences similar. Remember that we write V/T to sign

What is said to be side effect, What is said to be side effect? When a ...

What is said to be side effect? When a location other than one explicitly named in an instruction as a destination operand is affected, the instruction is said to have a side e

How many number of flip flops contained in IC 7490, The number of flip flop...

The number of flip flops contained in IC 7490 is ? Ans. 2 flip flops contained in IC 7490.

How a typical dma controller can be interfaced to an 8086, Demonstrate how ...

Demonstrate how a typical DMA controller can be interfaced to an 8086/8085 based maximum mode system.  For 8088 in maximum mode: The RQ/GT0 and RQ/GT1 pins are used to is

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd