input device with the output device or vice-versa. In order to make it simpler, Intel has designed A chip to interface I/O devices. The Intel A is a general. A Programmable Peripheral Interface in Microprocessor – A Programmable Peripheral The following figure shows the architecture of A −. The (or i) programmable peripheral interface (PPI) chip was developed and manufactured by Intel The PPI chip Architecture.

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Embedded Systems Practice Tests. Retrieved from ” https: Evolution of Microprocessor History of the microprocessor!

Explain with block diagram working of PPI.

The Intel or i Programmable Peripheral Interface PPI chip was developed and manufactured by Intel in the first half of the s for the Intel microprocessor. Microprocessor Interview Questions.

In essence, the CPU “outputs” a control word to the In this mode, the may be architectuer to extend the system bus to a slave microprocessor or to transfer data bytes to and from a floppy disk controller. So, without latching, the outputs would become invalid as soon as the write cycle finishes. Two 8-bit ports and two 4-bit port Any port can be input or output.

All of the output registers, including the status flip-flops, will be reset whenever the mode is changed. They are normally connected to the least significant bits of the address bus A0 and A1.


8255A Programmable Peripheral Interface Microprocessor

For port Adchitecture in this mode irrespective of whether is acting as an input port or output portPC0, PC1 and PC2 82255 function as handshake lines. Embedded Systems Interview Questions. It was later cloned by other manufacturers. All of these chips were originally available in a pin DIL package. Each line of archltecture C PC 7 – PC 0 can be set or reset by writing a suitable value to the control word register. It is an active-low signal, i. Analog Communication Interview Questions.

The A contains three 8-bit ports AB, and C. Popular Tags Blog Archives. Each 4-bit architecrure contains a 4-bit latch and it can be used for the control signal output and status signal inputs in conjunction with ports A and B. The function of this block is to manage all of the Internal and External transfers of both Data and Control or Status words. They are normally connected to the least significant bits of the address bus A0 and A1.

This tri-state bi-directional buffer is used to interface the internal data lilts of to the system data bus. Both “pull-up” cihp “pull-down” bus-hold devices are present on Port A. This page was last edited on 23 Septemberat If an input changes while the port is being read then the result may be indeterminate.


The Control Word Register can only be written into.

This 3-stable bi-directional 8-bit buffer is used to interface the A to the systems data bus. Intel Programmable Interval Timer.

Programmable Peripheral Interface(PPI) ~ Tutorial of Microprocessor, assembly etc.

They can be connected to peripheral devices. Analogue electronics Practice Tests. Share to Twitter Share to Facebook.

Microprocessor And Its Applications. This means that data can be input or output on the same eight lines PA0 – PA7. A “low” on this input pin enables the CPU to write data or control words into the Interrupt logic is supported. Digital Logic Design Practice Tests. Since the two halves of port C are independent, they may be used such that one-half is initialized as an input port while the other half is initialized as an output port.

When we wish srchitecture use port A or port B for handshake strobed input or output operation, we initialise that port in mode 1 port A and port B can be initilalised to operate in different modes, i.

Port C can be spitted into two parts and each can be used as control signals for ports A and B in the handshake mode.