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how can i made ismplest circuit for multiplication,division,and exchange of bits

S

sakshi

Jan 1, 1970
0
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id
 
J

John Larkin

Jan 1, 1970
0
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id

Some things just aren't simple.

John
 
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id

Use a microcontroller. Simple. One chip and a couple of external
components will do all of this and much more.

BRW
 
E

Eeyore

Jan 1, 1970
0
sakshi said:
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id

It's called a microprocessor.

Graham
 
C

Chris

Jan 1, 1970
0
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id

The microprocessor was invented to solve this problem, and it's
composed of logic gates.

http://www.intel.com/museum/archives/4004.htm

Let it go. There's no reason to do this except as a useless exercise,
kind of like chewing a case of gum.

Cheers
Chris
 
S

sakshi

Jan 1, 1970
0
Use a microcontroller. Simple. One chip and a couple of external
components will do all of this and much more.

BRW

thanks i dont want to use the programming of microcontroller we can do
this by also calculater but i want to make it just by the help of
digital electronics eg gates adders,shift register etc
 
S

sakshi

Jan 1, 1970
0
The microprocessor was invented to solve this problem, and it's
composed of logic gates.

http://www.intel.com/museum/archives/4004.htm

Let it go. There's no reason to do this except as a useless exercise,
kind of like chewing a case of gum.

Cheers
Chris

actually its a trainer board expereiment for the BE/BSC students in
lab thats why i want to design it.
 
E

Eeyore

Jan 1, 1970
0
sakshi said:
thanks i dont want to use the programming of microcontroller we can do
this by also calculater but i want to make it just by the help of
digital electronics eg gates adders,shift register etc

That's simply not realistic.

Graham
 
D

Dan Coby

Jan 1, 1970
0
sakshi said:
.... snip ...
actually its a trainer board expereiment for the BE/BSC students in
lab thats why i want to design it.

As everyone has pointed out, if you are trying to multiply very many bits
then you will need a lot of gates.

If you really want to build a multiplier using gates and adders then you
should remember how you were taught to multiply back in grade school.
You form rows which contain the first value multiplied by the digits of the
second value. You then add the rows. In binary you multiply 1 bit at a time.
In binary, a 1 bit value multiplied by a second 1 bit value is simply an AND
gate.

For instance if you want to build a 4 x 4 bit multiplier, you will form four rows.
You will need 16 AND gates to do the individual bit multiplications and
three adders to add the rows together.

There are schemes that use a single adder and serialize the addition
of the rows. However then you would need a register to hold intermediate
results and control logic for the serialization.

Now if you want a real challenge: I taught for a couple of years (76 to 78)
at a small university in western Kentucky. When I got there, there was a
RPG 30 computer in the corner of one of the labs. It was built in the 50's.
It had tubes, semi-conductor diodes, and a drum for memory and working
registers. It was capable of doing a 32 x 32 multiply and a 64 / 32 bit divide.
It only had SEVEN inverters for the entire computer. Inverters required tubes
so they tried to minimize them. Try to build a 64 / 32 bit divider with only seven
inverters (including the inverters hidden inside of your adders, etc.).
Hint: The accumulator and the memory was on a drum so that they could do
bit serial operations. Still I was extremely impressed that they could design
an entire computer with only seven inverters.
 
S

Stephen J. Rush

Jan 1, 1970
0
actually its a trainer board expereiment for the BE/BSC students in
lab thats why i want to design it.

For a trainer, it is practical to multiply bytes using an adder and two
shift registers. The algorithm goes something like this:

1. put the multiplicand in a register or have it available on input
switches

2. put the multiplier in a shift register.

2. Inspect the least-significant bit of the multiplier. If it's 1, add
the multiplicand to bits 7..15 of a 16-bit circular shift register, with
the carry going to bit 0.

3. If you haven't looked at the last multiplier bit yet, shift the 16-bit
register 1 bit to the right, shift the multiplier 1 bit to the right
and go to step 2.

After eight shifts, the 16-bit product will be in the circular register.
Instead of using a shift register for the multiplier, you can use a
counter and a multiplexer to point to each multiplier bit.

Four-bit parallel adders and eight-bit shift registers with both serial
and parallel inputs and outputs are available as single chips, so this
isn't hard to breadboard.

It would be instructive to build this, then solve the same problem in
assembly language on a 16-bit microcontroller, then on something like a
BASIC Stamp. I haven't done the cost and timing analyses, but the
microcontroller approach is probably the cheapest. The medium-scale
registers approach could be fastest. Some logic families have
sub-nanosecond gate propagation times, but I doubt that you could make
that work on a breadboard. A BASIC-interpreting microcontroller like the
Stamp would be slower and pricier, but definitely the quickest to
implement.
 
A

anirudh

Jan 1, 1970
0
hello guys
if we want to make the circuit for multiplication ,division ,exchange
of bitsusing gates which should be simple in design please send
information to my email id
The trouble would be to do all of addition,subtraction,multiplication
and division.You can use the same circuit for adding/subtracting.The
multiplication and division circuits are also very similar.Stephen
gave an algorithm for multiplication using a shift register in his
post.The algorithm for division is very similar.
However,as people have already pointed out ,for higher values of bit-
length(my guess is anything over 8-bits would be a problem on a
breadboard),the circuit will get very cumbersome.

If you actually want to try out this circuit,your best bet is either a
simulator or a microcontroller/procesor.

Any digital circuit simulator will allow you to draw the schematic of
the circuit and then simulate its behaviour over time.TkGate is one
such free program under linux that we used in our lab,but there are a
lot of commercial programs that do this too.

If you want to try this out on a microcontroller,then the PIC
controller would be your best bet.You can order free samples on their
website,which will generally reach in 3-4 days(they ship from
thailand).You can find a lot of circuits for pic programmers on the
net,but the one that has the least components(and IMHO works the best
too) is at http://pic16f84.hit.bg/
It uses only 7 components and works through the serial port(you might
have to find an old computer).You can program the PIC in C,so it
should'nt be too tough.sdcc will work as a c compiler under linux,and
there are lot of custom compilers for the PIC under windows as well.

Still I was extremely impressed that they could design
an entire computer with only seven inverters.
that is really cool!
 
R

Rich Grise

Jan 1, 1970
0
thanks i dont want to use the programming of microcontroller we can do
this by also calculater but i want to make it just by the help of
digital electronics eg gates adders,shift register etc

But then, if we did your homework for you, you wouldn't learn what
the course is trying to teach you, i.e., how to do logic design.

Good Luck!
Rich
 
J

Jasen Betts

Jan 1, 1970
0
thanks i dont want to use the programming of microcontroller we can do
this by also calculater but i want to make it just by the help of
digital electronics eg gates adders,shift register etc

how many bits is the width of the input ?

Bye.
Jasen
 
J

Jonathan Kirwan

Jan 1, 1970
0
actually its a trainer board expereiment for the BE/BSC students in
lab thats why i want to design it.

Depending on your familiarity, you might first try reading "Bebop
BYTES Back: An Unconventional Guide to Computers" from Doone
Publications as a very good and very detailed introduction to simple
processor design (no multiplier here, though, just basic education.)

For an early introduction to VHDL and Verilog in "parallel form" to to
find several good examples of a multiplier that is easy to understand
and well-described, try "HDL Chip Design" by Douglas Smith. It's one
of the earlier books on VHDL and verilog that made it into book
distribution after some of the pricing on compilers started reaching a
price a hobbyist might consider. There may very well be much better
books around, but this one is probably right at your level and it
provides not only VHDL and Verilog examples, it also includes the
logic diagrams, as well as a rather long description through the
details of a multiplier.

Jon
 
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