Interfacing of 4x4 matrix keyboard and 4 digit 7 segment display

• 4 scan lines are sufficient to scan matrix keyboard and to select display digits. Hence decoded mode is used.

Block diagram of ADC0809/ADC0808

Interfacing of 8255 with 8085 processor

INTERFACING OF 8X8 MATRIX KEYBOARD IN INTERRUPT KEYBORD MODE

Intel 8279 Keyboard/Display Controller

• The Intel 8279 is a Keyboard/Display Controller is specially developed for interfacing keyboard and display devices for the Intel 8085, 8086 and 8088 microprocessors

• Simultaneous keyboard and display operations

• Scanned keyboard mode.

• Scanned sensor mode.

• 8-character keyboard FIFO.

• Right or left entry 16-byte display RAM.

• Programmable scan timing.

PINOUT OF PIC 16F876

ARCHITECTURE OF PIC 16F876