This document discusses microprocessors and microcontrollers. It covers the 8085 microprocessor and 8051 microcontroller. It includes block diagrams and descriptions of the internal architecture and pin configurations of both chips. It also provides the timing diagram of the 8085 microprocessor machine cycles and discusses the 8255 Programmable Peripheral Interface chip including its pin configuration and block diagram. Examples are given of interfacing a keyboard, seven segment display, temperature sensor, and stepper motor with microcontrollers.

1. ME 6702 – MECHATRONICS
Prepared by,
L.Loganathan,AP/Mech,
Kamaraj college of Engg and
Tech.

2. UNIT-II
MICROPROCESSOR(8051) &
MICROCONTROLLER (8051)

3. IMPORTANT QUESTIONS
• Draw the internal block of 8085 microprocessor & explain each block.
• Explain the pin configuration of 8085 microprocessor.
• Explain addressing modes and its types.
• Explain the timing diagram of 8085 microprocessor with machine cycle
• Explain the architecture of 8051 microcontroller with block diagram.
• Explain the pin configuration of 8051 microcontroller.

4. Pin configuration
of 8085
microprocessor
a) Power supply
b) Frequency signals
c) Data bus
d) Address bus
e) Control bus
f) Interrupt signal
g) Serial I/O signal
h) DMA signal
i) Reset Signal

5. Architecture of 8085 microprocessor

6. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S
1
S
2
R
D
W
R
INTA
1 Opcode fetch 0 1 1 0 1 1
Memory read 0 1 0 0 1 1
3 Memory write 0 0 1 1 0 1
4 I/O read 1 1 0 0 1 1
5 I/O write 1 0 1 1 0 1
6 InterruptACK 1 1 1 1 1 0
7 Bus idle 1 1 1 1 1 1
Machine Cycle
1 Opcode fetch
2 Memory read
3 Memory write
4 I/O read
5 I/O write
6 InterruptACK
7 Bus idle

7. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S1 S2 RD WR INTA
1 Opcode fetch 0 1 1 0 1 1

8. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S1 S2 RD WR INTA
2 Memory read 0 1 0 0 1 1

9. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S1 S2 RD WR INTA
3 Memory write 0 0 1 1 0 1

10. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S1 S2 RD WR INTA
4 I/O read 1 1 0 0 1 1

11. TIMING DIAGRAM
S.No Machine Cycle
Status Control
IO/m S1 S2 RD WR INTA
5 I/O write 1 0 1 1 0 1

12. Pin configuration
of 8051
microcontroller
a) Power supply
b) Port 0 (P0.0 to P0.7)
c) Port 1(P1.0 to P1.7)
d) Port 2 (P2.0 to P2.7)
e) Port 3 (P3.0 to P3.7)
f) ALE/Prog
g) XTAL1 & XTAL2
h) PSEN
i) EA/VPP
j) RST

13. Architecture of 8051
microcontroller

15. PROGRAMMABLE
UNIT-III PERIPHERAL
INTERFACE

16. Pin configuration
of 8255 PPI
a) Power supply
b) Port A (PA0 to PA7)
c) Port B(PB0 to PB7)
d) Port C(PC0 to PC7)
e) Data bus buffer
f) Read
g) A1,A0
h) Write
i) Chip select
j) RST

17. Block Diagram of 8255
PPI

18. W
O
R
K
I
N
G

19. W
O
R
K
I
N
G

20. W
O
R
K
I
N
G

21. W
O
R
K
I
N
G

22. W
O
R
K
I
N
G

23. W
O
R
K
I
N
G

24. Interfacing a keyboard & a seven segment
display

25. Truth Table of seven segment
display

26. Interfacing a Temperature sensor with
8051

27. Interfacing a Stepper motor with
8051
X1
X2
Y1 Y2