1204 Ppi 8255 visit: www.techbed.blogspot.com

1. Programmable Peripheral Interface Devices Support chips : 8155 , 8255 , 8279 , 8254 , 8257 , 8259,8251

4. I/O Interfacing using 8255 8085 8255 8-bit ADC System Bus LED DISPLAY Temperature Sensor Port A Port C u Port B Port C l

5. Interfacing with Analog-to-Digital Converter 8085 8255 8-bit ADC System Bus Temperature Sensor Port A Port C lines SOC EOC OE

8. 1. Configure 8255 I/O Ports 8085 8255 8-bit ADC System Bus LED DISPLAY Temperature Sensor Port A Port C u Port B Port C l

12. for Parallel I/O 1 0 0 0 1 00 1 91H

13. for Bit Set/Reset Mode

19. Pin diagram of 8255 D7 – D0 Data Bus PA7 – PA0 Port A PB7 – PB0 Port B PC7 – PC0 Port C CS Chip Select A0, A1 Address bits RD Read Input WR Write Input RESET Reset Input Vcc +5V GND 0 Volts

22. 8255 Chip selection & Port Addresses 8255 A2 A3 A4 A5 A6 A7 CS A1 A0 A1 A0 A = 80H B = 81H C = 82H A1 A0 Port 0 0 A 0 1 B 1 0 C 1 1 CWR

24. Block diagram of 8255