1. 8051 Microcontroller Pin Diagram and PSW Register

2. Objectives of Lecture Function of each pin of 8051 Format of PSW Register Understand function of each bit

3. Pin Diagram of 8051 Intel 8051 is a pin 40 pin IC available in Dual-In line package (DIP) Requires a single power supply of +5V. EA (Low)/Vpp =1 pin is used to supply programming voltage +12V to EPROM/ROM. PSEN: It is used to enable external program memory (ROM). It is connected to (OE) of external ROM. Address latch enable: It is used to demultiplex address and data bus. Thus it separates A0-A7 address from AD0- AD7.

4. Format of Program Status Word Register CYACF0RS1RS0OV-P D7 D6 D5 D4 D3 D2 D1 D0 1 1 1 1 0 1 0 1 + 1 0 0 0 1 0 1 0 ______________ 1 0 1 1 1 1 1 1 1 CY 1

5. Format of Program Status Word Register CYACF0RS1RS0OV-P D7 D6 D5 D4 D3 D2 D1 D0 CY 1 1 1 0 1 1 1 0 1 + 0 0 0 0 1 0 1 0 ______________ 0 1 1 1 0 1 1 1 1

6. Format of Program Status Word Register CYACF0RS1RS0OV-P D7 D6 D5 D4 D3 D2 D1 D0

7. Format of Program Status Word Register CYACF0RS1RS0OV-P D7 D6 D5 D4 D3 D2 D1 D0 1 0 0 1 0 1 0 0 P=1 1 1 0 1 0 1 0 0 P=0

8. Thank you