1. GOOD JOB……..
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2. 8085
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3. Evolution of Intel Microprocessor………..
4004 8008 8080 8086 8086
Introduced 15/11/ 1/4/72 1/4/74 8/6/74 1/6/79
71
Clock 108 108 2 MHz 5,8,10 5,8
speed
kHz kHz MHz MHz
Bus Width 4 bits 8 bits 8 bits 16 bits 8 bits
Number of 2300 3500 6000 29,000 29,000
transistor
(microns)
(10) (6) (3) (3)
Addressabl 640 16kbyt 64kbyte 1MB 1MB
e
Memory
bytes es s
Virtual _ _ _ _ _
Memory
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4. 1980 Intel processor……………….
80286 386 TM DX 386 TM SX 4867 H DX
CPU
Introduced 1/2/82 1/10/85 16/6/88 10/4/89
Clock speed 6,1.2,5MHz 16-33MHz 16-33MHz 25-50MHz
Bus width 16 bits 32bits 16bits 32bits
Number of 134,000(1. 275,000(1) 275,000(1) 1.2
Transistor 5) Million(10.8-
(microns) 1)
Addressable 16MB 4GB 4GB 4GB
memory
Virtual 1GB 64TB 64TB 64TB
memory
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5. 1990 Intel processor……………………….
486 TM SX Pentium Pentium I Pentium II
Introduced 22/4/91 22/3/93 01/11/95 07/5/97
Clock 16-133 60- 150- 200-
Speed MHz 166MHz 200MHz 300MHz
Bus Width 32 bits 32bits 64 bits 64 bits
Number of 1.185 3.1 5.5 7.5
Transistor( Million(1) Million(.8) Million(0.6) Million(1.35
microns) )
Addressabl 4GB 4GB 64GB 64GB
e Memory
Virtual 64TB 64TB 64TB 64TB
Memory
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6. 2000 Intel Processor………………
Pentium III Pentium 4
Introduced 26/2/99 25/11/2000
Clock speed 450-660MHz 1.3-1.8GHz
Bus Width 64 bits 64 bits
Number of 95 Million 64 Million
Transistor(micro
ns)
Addressable 64GB 64GB
memory
Virtual Memory 64 TB 64 TB
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7. 1.It has an 8-bit MICROPROCESSOR, it provides 8-bitsdata.
2.It operate in a single +5V power supply at Vcc and
ground to Vss.
3.It operates on clock cycle with 50% duty cycle.
4. It has on chip clock generator, it contain like LC ,RS
or crystal .
5.It can operate with 3mhz clock frequency.
6.It contain 16 bits address line , 8 bits data line and
64 Kbytes memory and 256 i/o ports.
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8. 7.It support 74 instructions with the following addressing
modes:
a) Immediate b) Register c) Direct d) Indirect e)
Implied
8. The ALU of 8085 performs.
a) 8 bits binary addition with or without carry
b) 16 bits binary addition c) 2 digit BCD addition
d) 8 bits binary subtraction with or without borrow .
e)8 bits logical AND,OR EX-OR COMPLEMENT (NOT) and
bit shift operation.
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9. 9. It has 8-bit accumulator ,flag register ,instructional register ,
six 8-bit general register(B,C,D,E.H)AND 16 BITS register (SP and
PC)
10. It provides five hardware interrupts :TRAP,RST7.5,RST 6.5,
RST 5.5 and INTR.
11. IT has serial I/O control signal.
12. It provides control signals (IO/M, RD WR,) to control
the bus cycles and so external bus controller is not
required.
13. It can be used to implemented three chip
microcomputer with supporting I/O device like IC 8155
and 8355
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10. ARCHITECTURE OF 8085 :
It consist of various functional blocks as listed below :
•Registers
•Arithmetic and logic unit
•Instruction decoder and machine cycle encoder
•Address buffer
•Address/data buffer
•Incrementer/decrementer address latch
•Interrupt control
•Serial I/O control
•Timing and control circuitry.
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11. INTR INTA RST5.5 RST6.5 RST7.5 TRAP SID SOD
8 Bit internal data bus
ACCUMULAT TEMP FLAG W Reg Z Reg
INST Reg.
OR Reg. Reg. B Reg C Reg
D Reg E Reg
INSTRUCTI H Reg L Reg
ON STACK
ALU DECODER POINTER
&MACHINE
CYCLE
PC
INCREMENTER/DE
ENCODER
CREMENTER
POWER +5V ADDRESS LATCH
SUPPLY GND
TIMING AND CONTROL
X1 CLK GEN CONTROL STATUS DMA ADD ADD/DATA
X2 RESET BUFFER BUFFER
A A
RD
CLK OUT WR ALE
SO S1IO/M 15- 8
READY
HLDA RESET OUT
HOLD RESET IN ADDRESS BUS
AD7-AD0
DATA/ADD BUS 11
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12. The 8085 register are classified as……….
1 . General purpose Registers( A,B,C,D,E,H and L 8
OR 16 Bits reg.)
2. Temporary Register
a) Temporary data Register b) W and Z Register
3. Special purpose Registers
a) Accumulator b) Flag Register ( S,Z,AC,P,CY,-Sign flag)
c) Instruction Register
4) Sixteen Bit Register
a) Program Counter b) Stack Pointer
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13. 1. 16 bit Registers…………
a) Program Counter (PC): Program is a sequence of
instruction ,it store the address
of the next instruction at a given time.
b) Stack Pointer(SP): It Reserved area of the memory in the
RAM where temporary information may
be stored.
2. Arithmetic Logic Unit(ALU): It perform bitwise
fundamental arithmetic operation such
as ADD,SUB… Also perform logic
operation AND,OR, EX-OR.
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14. 3. Instruction Decoder : It store opcode, then sent to inst
decoder.Inst decoder decodes it and
accordingly gives timing and control
signals which control the register,
the data buffer,ALU and External signal
depend on nature of the instruction.
4. Address Buffer : It is 8 bit unidirectional buffer .it is used to drive
external high order address bus (A15-A 8).
5.Address/Data buffer : It is Bi- Directional buffer ,it is
used to drive multiplexed address/data bus, low order
(A7-A0) and data bus (D7-D0).
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15. 6. Incrementer/decrementer Address Latch : The 16 bit register is used
to increment and decrement the content of program
counter or stack pointer as a part of execution of inst
related to them.
7. Interrupt Control : The processor fetch ,decodes and executes Instruction
in a sequence. Its having special routine Whenever
special condition exits within a program.
8. Serial I/O Control : it is used for long distance data transmission and
communication .it provides two lines SOD and SID for
serial communication. SOD(Serial output data) is used
for send data serially and SID(Serial Input data)
line used to receive data serially.
9. Timing and control circuitry: it is responsible for all the operations
such as control of fetching ,decoding operation,
generating appropriate signals for inst execution.
10.Power Supply and Frequency signals: It requires +5v .
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16. A6-A1(ADDRESS BUS)
AD0-AD7( I/0 3 STATE Multiplexed add/data bus)
ALE( output Address Latch Enable)
S0-S1(output data bus Status)
S1 So
0 0 HALT
0 1 WRITE (S1 Used for advance R/W status)
1 0 READ
1 1 FETCH
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17. RD (READ OUTPUT)
WR ( WRITE OUTPUT)
READY( INPUT)
HOLD(INPUT)
HLDA (OUTPUT)
INTR-INTERRUPT REQUEST ( INPUT)
INTR-INTERRUPT ACKNOWLEDGE (OUTPUT)
1) RST 7.5
2) RST 6.5(INPUT)
3) RST 5.5
 RESTART INTERRUPTS
1) RST 7.5(HIGHEST PRIORITY)
2) RST 6.5(INPUT)
3) RST 5.5(LOWEST PRIORITY)
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18. TRAP (INPUT)
RESET IN (INPUT)
RESET OUT(OUTPUT)
X1,X2 ( INPUT)
CLK (OUTPUT)
IO/M (OUTPUT)
SID (OUTPUT)
SOD (OUTPUT)
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