how to increase I/O pins in microcontroller

Hello ,

Can any one tell me how should i increase the i/o pin for at89c51 microcontroller ?
what should i interface ?

Thank you.

devmania said:

Hello ,

Can any one tell me how should i increase the i/o pin for at89c51 microcontroller ?
what should i interface ?

Thank you.

Click to expand...

hi,
You could use Shift Registers or Encoder IC's
HEF4057 or 74HC595 types

Thanks Eric,

But will i be able to interface it with At89c51 or not? If ii can please tell me how?
Thank you.

devmania said:

Thanks Eric,

But will i be able to interface it with At89c51 or not? If ii can please tell me how?
Thank you.

Click to expand...

hi,
The IC's I suggested are both CMOS types so they should be fully compatible with the 89C51.
For the HEF4067 you could use 4 port pins to select up to 16 analog/digital I/O's
The 74HC495, a 8951 pin for a clock, 1 Dout, 1 Dinp this would give up to 8 digital I/O's. The 495 can be connected in series with another 495 ...

Is this what you are asking.?

EDIT:
Something like this. or this...

You can also use 8255 (bit old)