Programmable Peripheral Interface 8255
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The document discusses the Programmable Peripheral Interface 8255 (PPI), which is an I/O port chip used for interfacing I/O devices with microprocessors. It has 24 pins for I/O that are programmable in groups of 12 pins and has three distinct modes of operation. The PPI is commonly used in microprocessor labs for interfacing experiments and knowledge of it is essential for students. It describes the basic modes of operation and how to program the 8255.
Programmable Peripheral Interface 8255
- 1. 1 PROGRAMMABLE PERIPHERAL INTERFACE - 8255 Department of Mechanical Engineering DHIRAJLAL GANDHI COLLEGE OF TECHNOLOGY Name of Faculty : Dr.P.Parandaman Designation : Associate Professor Department : Mechanical Engineering Year/Semester : IV /VII
- 3. Intel 8255 PPI PPI – Programmable Peripheral Interface It is an I/O port chip used for interfacing I/O devices with microprocessor Very commonly used peripheral chip Knowledge of 8255 essential for students in the Microprocessors lab for Interfacing experiments 3
- 4. About 82C55 • The 82C55 is a popular interfacing component, that can interface any TTL-compatible I/O device to a microprocessor. • It is used to interface to the keyboard and a parallel printer port in PCs (usually as part of an integrated chipset). • Requires insertion of wait states if used with a microprocessor using higher that an 8 MHz clock. • PPI has 24 pins for I/O that are programmable in groups of 12 pins and has three distinct modes of operation.
- 5. 8255 : Pin Layout
- 12. Basic Mode Definitions and Bus Int • Mode 0 – Basic I/O • Mode 1 – Strobe I/O • Mode 2 – Bi-Dir Bus
- 13. 11-13 Programming 8255 8255 has three operation modes: mode 0, mode 1, and mode 2
- 47. 47 Department of Mechanical Engineering