• June 19, 2019

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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They can be configured as either as input or output ports.

Intel 8255

Each port uses three lines from ort C as handshake signals. Its contents lntel the working of Auth with social network: Port A uses five signals from Port C as handshake signals for data transfer. If an input changes while the port is being read then the result may be indeterminate.

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Intel A Programmable Peripheral Interface

For example, if port B and upper port C have to inrel initialized as input ports and lower port C and port A as output ports all in mode Requires insertion of wait states if used with a microprocessor using higher that an 8 MHz clock. Bit 7 of Port C. This interrupts the processor.

Interrupt logic is supported. Retrieved 3 June Retrieved from ” https: PC are used as handshake signals by Port A when configured in Mode 2. As an example, consider an input device connected to at port A. Acknowledgement and handshaking signals are provided to maintain proper data flow and synchronisation between the data transmitter and receiver.


PPI PPI Programmable Peripheral Interface. – ppt video online download

Port A can be used for bidirectional handshake data transfer. We think you have liked this presentation. To make this website work, we log user data and share it with processors.

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. My presentations Profile Feedback Log out. To use this website, you must agree to our Privacy Policyincluding cookie policy. It is used to interface to the keyboard and a parallel printer port in PCs usually as part of an integrated chipset. This is required because the data only stays on the bus for one cycle. Input and Output data are latched.

8255 PPI PPI Programmable Peripheral Interface.

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 lntel referenced at a later time. Some of the pins of port C function as handshake lines.

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. 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.

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If from the previous operation, port A is initialized as an output port and if is not reset before using the current configuration, then there is a possibility inntel damage of either the input device connected or or both, since both and the device connected will be sending out data.

So they are shown as X Required MD control word: 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. The features of the mode include the following: Registration Forgot your password? If the Port interrupt is enabled, INT is activated.

Inputs are not latched. By using this site, you agree to the Terms of Use and Privacy Policy. It is an active-low signal, i.

Retrieved 26 July Input and Output data are latched. From Wikipedia, the free encyclopedia. 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. The ‘s intl are latched to hold the last data written to them.