Description of 8253 timer

MicrocontrollerMicroprocessor8085

As a DIP package Intel 8253 is a 24-pin programmable IC available. IChas three counters which work independently and whose width is of16-bits. In addition, we have a control port to decide what is the mode of working of the three counters. The physical and functional pin diagrams of them are indicated below.

Fig.Diagram of 8253 pin based

Fig.Pin diagram functional

Vcc and Gn
These are the Power supply and ground pins which 8253 uses +5V as power supply
D7-0
For the communication of the processor there are eight functional pins
RD*
This reads counter information it is active low pin
WR*
Writes control information
CS*
It selects the chip which is also active low pin
A1,A0
These are the address input pins.
CLK0
Clock input is provided for counter 0
CLK1
Clock input is provided for counter 1
CLK2
Clock input is provided for counter 2
Gate0
Controls counter function 0
Gate1
Controls function of counter 1
Gate2
Controls function of counter 2
Out0
Here counter 0 sends  output
Out1
Here counter 1 sends  output
Out2
Again counter 2 sends the output
raja
Published on 21-Jan-2019 15:53:54
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