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communication between the A and the CPU. The A is a programmable peripheral interface. (PPI) device designed for use in Intel microcomputer. PPI is a general purpose programmable I/O device designed to interface the CPU with its outside world such as ADC, DAC, keyboard etc. We can program . PPI •The INTEL is a 40 pin IC having total 24 I/O pins. consisting of 3 numbers of 8 –bit parallel I/O ports (i.e. PORT A, PORT B.

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Each port uses three lines from ort C as handshake signals. All of these chips were originally available in a pin Ppj package. The functionality of the is now mostly embedded in larger VLSI processing chips as a sub-function. If you wish to download it, please recommend it to your friends in any social system.

Acknowledgement and handshaking signals are provided to maintain proper data flow and synchronisation between the data transmitter and receiver. This is required because the data only stays on the bus for one cycle. Auth with social network: This means that data can be input or output on the same intsl lines PA0 – PA7. Published by Loraine Cobb Modified over 3 years ago.

So they are shown as X Required MD control word: For port B in this mode irrespective of whether is acting as an input port or output portPC0, PC1 and PC2 pins function as handshake lines. To use this website, you must agree to our Privacy Policyincluding cookie policy.

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. Bidirectional Data Transfer This mode is used primarily in applications such as data transfer between two computers. This page was last edited on 23 Septemberat We think you have liked this presentation.


8255 PPI PPI Programmable Peripheral Interface.

Views Read Edit View history. Processor reads the port during the ISS. Since the two halves of port C are independent, they 855 be used such that one-half is intwl as an input port while the other half is initialized as an output port.

To make this website work, we log user data and share it with processors. There is also a Control port from the Processor intell of view. Opi can be configured as either as input or output ports. For example, if port B and upper port C have to be initialized as input ports and lower port C and port A as output ports all in mode The two halves of port C can be either used together as an additional 8-bit port, or they can be used as individual 4-bit ports.

Retrieved from ” https: When we wish to 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.

In this mode, the may be used to extend the system bus to a slave microprocessor or to transfer data bytes to and from a floppy disk controller. Processor reads the status of the port for this purpose Port A can be used for bidirectional handshake data transfer. By using this site, you agree to the Terms of Use and Privacy Policy. The chip poi circuit connected to the CS pin assigns addresses to the ports of The pp of the mode include the following: Interrupt logic is supported.


Port A uses kntel signals from Port C as handshake signals for data transfer. Required MD control word: As an example, consider an input device connected to at port A. Bit 7 of Port C.

Requires insertion of wait states if used with a microprocessor using higher intsl an 8 MHz clock. Some of the pins of port C function as handshake lines. The inputs are not latched because the CPU only has to read their current values, then store the data in a CPU register or memory if it needs to be referenced at a later time.

Processor sends another byte poi the port during the ISS. Microprocessor And Its Applications.

Get code and repeat in infinite loop. Each line of port C PC 7 – PC 0 can be set or reset by writing a suitable value to the control word register.

Interrupt logic is supported.

D – Programmable Peripheral Interface

So, without latching, the outputs inel become invalid as soon as the write cycle finishes. Its contents decides the working of It is used to interface to the keyboard and a parallel printer port in PCs usually as part of an integrated chipset. This interrupts the processor. The ‘s outputs are latched to hold the last data written to them.

Only port A can be initialized in this mode. Registration Forgot your password? Retrieved 26 July It is an active-low signal, i. When CS Chip select pip 0, is selected for communication by the processor.

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