It looks like you're missing the decimal to binary part?

What does the LCD want? Is it going to display a binary

number or decimal? Maybe you don't need to convert to

binary.

For concatenation, you would end up with binary-coded

decimal. If you're only using decimal numbers, look at

the low four bits only of each key-press. So your 42

would turn into 01000010, which is '42' in BCD. Multiplying

by two in BCD is not quite as simple as it would be in binary,

but if the LCD wants to display a decimal number, it is

probably easier than first converting '42' to binary, then

multiplying by two (shift left) and converting back to

decimal.

If you want to convert to binary, the common way it

would be done is to start with zero in an accumulator

and then at each keypress, multiply the accumulator

by 10 and add the new key value. Thus when you

start off, acc is '0' and when you press '4' you get

0 * 10 + 4 = 4. Then you press '2' and get 4 * 10 + 2

= 42. You would then need logic to multiply and

display when the space key is pressed.

Good Luck,

Gabor

Rishi Dhupar wrote:

> Well my professor gave me the keyboard and lcd driver to use.

>

> I just have to make the interface to connect them. The keyboard

> driver outputs the 8 bit binary value to which key is pressed.

>

> So for instance I press "4" on the key, my interface would get 00000100

> then I press 2, it would get 00000010. So you are saying I need to

> concatanate these two? That doesn't make sense, putting them together

> wouldn't get me 42.

>

> I would need to get 00101010 (42d) and then I know how to do the rest

> from that.

>

> Am I missing something?

>

> Thanks,

>

> Rishi

>

>

>

>

>

>

> Rob wrote:

> > Have you written any code that you could offer up for review? Are your

> > simulations not producing the output you would expect?

> >

> > If you wish to put multiple values together into one larger word, search the

> > various verilog websites for "concatenation".

> >

> >

> >

> > "Rishi Dhupar" <[email protected]> wrote in message

> > news:[email protected] ups.com...

> > > Hi,

> > >

> > > Trying to figure out how I can concatanate input from a keyboard. I

> > > cannot seem to figure out how I would store the number "12" from

> > > keyboard input. The user presses 1, gets stored somewhere then he

> > > presses 2, then that gets stored somewhere. How can I like put these

> > > together so verilog knows it is "12"?

> > >

> > >

> > > Basically I am just doing keyboard input to LCD output.

> > > Type in a 3 digit number on KB and press the space key, and it should

> > > print out the number * 2 to the LCD.

> > >

> > >

> > > Thanks for any help.

> > >

> > >

> > > Rishi Dhupar

> > >