for electrical and electronics engineering students

1. Internal Architecture And
Pin configuration of 8085
Microprocessor
Prepared By:-
Shraddha Aron
(1401421065)
EN-1

2. CONTENTS
• Microprocessor
• Internal architecture of 8085
microprocessor
• Register structure
• 8085 pin configuration
• Address Bus
• Control and Status signals
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3. CONTENTS
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• Power supply and clock frequency
• Externally initiated signals and
interrupts
• Serial I/O Port
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4. MICROPROCESSOR
With the advancement of
microelectronics technology, it become
possible to integrate ALU, control
circuits & memory on a single silicon
chip. This IC chip is called
microprocessor.
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5. MICROPROCESSOR 5

6. 8085
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OR

7. • The 8085 is an 8-bit general purpose
microprocessor that can address
216
=64K Byte of memory.
• It has 40 pins and uses +5V for power.
It can run at a maximum frequency of
3 MHz.
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8. INTERNAL
ARCHITECTURE
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9. MICROPROCESSOR 9

10. It consists of various functional
blocks as listed below –
• Registers
• Arithmatic and Logic Unit
• Instruction Decoder & Machine cycle
encoder
• Address Buffer
• Address/Data Buffer
• Incrementer/Decrementer Address
Latch MICROPROCESSOR 10

11. • Interrupt Control
• Serial I/O Control
• Timing & Control circuitary
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12. REGISTER STRUCTURE
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13. 8085 registers are classified as-
General Purpose registers
Temporary registers
1. Temporary data register
2. W & Z registers
Sixteen bit registers
1. Program Counter
2. Stack Pointer
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14. Special Purpose registers
1. Accumulator
2. Instruction register
3. Flag registers
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15. MICROPROCESSOR
8085 PIN
CONFIGURATION
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16. MICROPROCESSOR 16

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18. ADDRESS BUS
8085 has 16 signal lines that are used as
address bus; however, these lines are
split into two segments: and
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815 AA −
07 ADAD −
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19. CONTROL & STATUS
SIGNALS
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This gp. of signals includes two control
signals ( and ), three status
signals(IO/ , and ) to identify the
nature of the operation and one special
signal (ALE) to indicate the beginning of
the operation.
RD WR
0S
M 1S 0S
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20. POWER SUPPLY AND
CLOCK FREQUENCY
The power supply and frequency signals
are as follows :-



CLK(OUT)
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CCV
SSV
21andXX
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21. EXTERNALLY INITIATED
SIGNALS AND INTERRUPTS
 INTR

 RST 7.5, RST6.5, RST 5.5
 TRAP
 HOLD
 HLDA
 READY
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INTA
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22. 
RESET OUT
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RESETIN
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23. SERIAL I/O PORT
8085 has two signals to implement the
serial transmission: SID and SOD
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24. THANK YOU…
ANY QUERIES
?..
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