UNIT-I MICROPROCESSOR PROGRAMMING AND STACK.pptx
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The document provides a detailed overview of the Intel 8086 microprocessor, which was released in 1978 and utilizes various addressing modes for programming, including immediate, direct, and indirect addressing among others. It explains the architecture, clock generation, memory access capabilities, and differencing between working in maximum and minimum modes, as well as interactions with co-processors like the 8087. Additionally, it covers how the processor operates in relation to memory addressing, effective address calculations, and I/O port addressing.
![1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
Here, the effective address of the memory
location at which the data operand is stored is
given in the instruction.
The effective address is just a 16-bit number
written directly in the instruction.
Example:
MOV BX, [1354H]
MOV BL,
[0400H]
The square brackets around the 1354H denotes
the contents of the memory location. When
executed, this instruction will copy the contents of
the memory location into BX register.
This addressing mode is called direct because the
displacement of the operand from the segment
base is specified directly in the instruction.
Group II : Addressing modes for
memory data
7](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-14-320.jpg)
![1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
register which holds the effective address (EA)
will be specified in the instruction.
Registers used to hold EA are any of the following
registers:
BX, BP, DI and SI.
Content of
the
DS
register
is used for base
Group II : Addressing modes for
memory data
In Register indirect addressing, name of
the
address calculation.
Example:
MOV CX, [BX]
Operations:
EA = (BX)
BA = (DS) x 1610
MA = BA + EA
(CX) (MA)
or,
(CL) (MA)
(CH) (MA +1)
Note : Register/ memory
enclosed in brackets refer to
content of register/ memory
8](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-15-320.jpg)
![9
1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
In Based Addressing, BX or BP is used to hold the
base value for effective address and a signed 8-bit
or unsigned 16-bit displacement will be specified
in the instruction.
In case of 8-bit displacement, it is sign extended
to 16-bit before adding to the base value.
When BX holds the base value of EA, 20-bit
physical address is calculated from BX and DS.
When BP holds the base value of EA, BP and SS is
used.
Example:
MOV AX, [BX + 08H]
Operations:
0008H 08H (Sign extended)
EA = (BX) + 0008H
BA = (DS) x 1610
MA = BA + EA
(AX) (MA) or,
(AL) (MA)
(AH) (MA + 1)
Group II : Addressing modes for
memory data](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-16-320.jpg)
![1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
SI or DI register is used to hold an index value for
memory data and a signed 8-bit or unsigned 16-
bit displacement will be specified in the
instruction.
Displacement is added to the index value in SI or
DI register to obtain the EA.
In case of 8-bit displacement, it is sign extended
to 16-bit before adding to the base value.
Example:
MOV CX, [SI + 0A2H]
Operations:
FFA2H A2H (Sign extended)
EA = (SI) + FFA2H
BA = (DS) x 1610
MA = BA + EA
(CX) (MA) or,
(CL) (MA)
(CH) (MA + 1)
Group II : Addressing modes for
memory data
17](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-17-320.jpg)
![1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
In Based Index Addressing, the effective address
is computed from the sum of a base register (BX
or BP), an index register (SI or DI) and a
displacement.
Example:
MOV DX, [BX + SI + 0AH]
Operations:
000AH 0AH (Sign extended)
EA = (BX) + (SI) + 000AH
BA = (DS) x 1610
MA = BA + EA
(DX) (MA) or,
(DL) (MA)
(DH) (MA + 1)
Group II : Addressing modes for
memory data
18](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-18-320.jpg)
![1. Register Addressing
2. Immediate Addressing
3. Direct Addressing
4. Register Indirect Addressing
5. Based Addressing
6. Indexed Addressing
7. Based Index Addressing
8. String Addressing
9. Direct I/O port Addressing
10. Indirect I/O port Addressing
11. Relative Addressing
12. Implied Addressing
These addressing modes are used to access data
from standard I/O mapped devices or ports.
In direct port addressing mode, an 8-bit port
address is directly specified in the instruction.
Example: IN AL, [09H]
Operations: PORTaddr = 09H
(AL) (PORT)
Content of port with address 09H is
moved to AL register
In indirect port addressing mode, the instruction
will specify the name of the register which holds
the port address. In 8086, the 16-bit port address
is stored in the DX register.
Example: OUT [DX], AX
Operations: PORTaddr = (DX)
(PORT) (AX)
Content of AX is moved to port
whose address is specified
by DX register.
Group III : Addressing modes for
I/O ports
20](https://image.slidesharecdn.com/unit-imicroprocessorprogrammingandstack-241217181203-ab7631f9/85/UNIT-I-MICROPROCESSOR-PROGRAMMING-AND-STACK-pptx-20-320.jpg)
UNIT-I MICROPROCESSOR PROGRAMMING AND STACK.pptx
- 2. INTEL 8086 16 BIT Processor. Released by INTEL 1978 Designed using HMOS technology. Now it manufactured using HMOS III technology. It contains 29000 transistor 40 pin DIP 5 Volt Supply
- 3. Clock signal is not generated internally. Requires an external asymmetric clock source with 30% duty cycle. 8284 clock generation is used to generate the required clock for 8086. Maximum internal clock 5MHz 8086-110MHz 8086-2 8 MHz 8086-4 4 MHz. 8086 uses a 20 bit address to access memory Memory capacity 2^ no.of address line =2 ^20=1 Mbyte. 8086 has two memory bankk512k byte each Two memory bank 1.Even 2.Odd
- 4. The address line A0 is used to select even bank. BHE’ is used for select odd bank. I/O access: Separate 16 bit address So generate 2^16 =64 k address. The signal M/I0’ is used to differentiate the memory & I/O adderess. M/Io’ high Memory adderss low I/O address Operating modes: Two modes 1. Maximum mode 2. minimum mode.
- 5. The mode is decided by a signal at MN/MX’ pin MN/Mx’ high minimum mode & system is called uni processor. MN/Mx’ low maximum mode multiprocessor. Normally MN/MX’ pin is permanently tied to low or high. So that 8086 system can work in any one of the mode. 8086 can work with 8087 co processor in maximum mode. 8086 has two family of processor 1.808616 bit data bus externally 2. 8088 uses 8 bit data bus externally 8086 access memory in words 8088 access memory in bytes. IBM designed 1st personal computer using INTEL 8088 microprocessor as CPU.
- 11. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing The instruction will specify the name of the register which holds the data to be operated by the instruction. Example: MOV CL, DH The content of 8-bit register DH is moved to another 8-bit register CL (CL) (DH) Group I : Addressing modes for register and immediate data 1
- 12. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing In immediate addressing mode, an 8-bit or 16-bit data is specified as part of the instruction 1 Example: MOV DL, 08H The 8-bit data (08H) given in the instruction is moved to DL (DL) 08H MOV AX, 0A9FH The 16-bit data (0A9FH) given in the instruction is moved to AX register (AX) 0A9FH Group I : Addressing modes for register and immediate data
- 13. 20 Address lines 8086 can address up to 1M bytes of memory 220 = However, the largest register is only 16 bits Physical Address will have to be calculated Physical Address : Actual address of a byte in memory. i.e. the value which goes out onto the address bus. Memory Address represented in the form – Seg :Offset(Eg - 89AB:F012) Each time the processor wants to access memory, it takes the contents of a segment register, shifts it one hexadecimal place to the left (same as multiplying by 1610), then add the required offset to form the 20- bit address 89AB : F012 89AB 89AB0 (Paragraph to byte 89AB x 10 = 89AB0) (Offset is already in byte unit) F012 0F012 + ------- 98AC2 (The absolute address) 16 bytes of contiguous memory 5
- 14. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing Here, the effective address of the memory location at which the data operand is stored is given in the instruction. The effective address is just a 16-bit number written directly in the instruction. Example: MOV BX, [1354H] MOV BL, [0400H] The square brackets around the 1354H denotes the contents of the memory location. When executed, this instruction will copy the contents of the memory location into BX register. This addressing mode is called direct because the displacement of the operand from the segment base is specified directly in the instruction. Group II : Addressing modes for memory data 7
- 15. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing register which holds the effective address (EA) will be specified in the instruction. Registers used to hold EA are any of the following registers: BX, BP, DI and SI. Content of the DS register is used for base Group II : Addressing modes for memory data In Register indirect addressing, name of the address calculation. Example: MOV CX, [BX] Operations: EA = (BX) BA = (DS) x 1610 MA = BA + EA (CX) (MA) or, (CL) (MA) (CH) (MA +1) Note : Register/ memory enclosed in brackets refer to content of register/ memory 8
- 16. 9 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing In Based Addressing, BX or BP is used to hold the base value for effective address and a signed 8-bit or unsigned 16-bit displacement will be specified in the instruction. In case of 8-bit displacement, it is sign extended to 16-bit before adding to the base value. When BX holds the base value of EA, 20-bit physical address is calculated from BX and DS. When BP holds the base value of EA, BP and SS is used. Example: MOV AX, [BX + 08H] Operations: 0008H 08H (Sign extended) EA = (BX) + 0008H BA = (DS) x 1610 MA = BA + EA (AX) (MA) or, (AL) (MA) (AH) (MA + 1) Group II : Addressing modes for memory data
- 17. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing SI or DI register is used to hold an index value for memory data and a signed 8-bit or unsigned 16- bit displacement will be specified in the instruction. Displacement is added to the index value in SI or DI register to obtain the EA. In case of 8-bit displacement, it is sign extended to 16-bit before adding to the base value. Example: MOV CX, [SI + 0A2H] Operations: FFA2H A2H (Sign extended) EA = (SI) + FFA2H BA = (DS) x 1610 MA = BA + EA (CX) (MA) or, (CL) (MA) (CH) (MA + 1) Group II : Addressing modes for memory data 17
- 18. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing In Based Index Addressing, the effective address is computed from the sum of a base register (BX or BP), an index register (SI or DI) and a displacement. Example: MOV DX, [BX + SI + 0AH] Operations: 000AH 0AH (Sign extended) EA = (BX) + (SI) + 000AH BA = (DS) x 1610 MA = BA + EA (DX) (MA) or, (DL) (MA) (DH) (MA + 1) Group II : Addressing modes for memory data 18
- 19. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing Employed in string operations to operate on string data. The effective address (EA) of source data is stored in SI register and the EA of destination is stored in DI register. 4. Register Indirect Addressing Segment register for calculating base address of source data is DS and that of the destination data is ES Example: MOVS BYTE Operations: Calculation of source memory location: EA = (SI) BA = (DS) x 1610 MA = BA + EA Calculation of destination memory location: EAE = (DI) BAE = (ES) x 1610 MAE = BAE + EAE (MAE) (MA) If DF = 1, then (SI) (SI) – 1 and (DI) = (DI) - 1 If DF = 0, then (SI) (SI) +1 and (DI) = (DI) + 1 Group II : Addressing modes for memory data Note : Effective address of the Extra segment register 19
- 20. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing These addressing modes are used to access data from standard I/O mapped devices or ports. In direct port addressing mode, an 8-bit port address is directly specified in the instruction. Example: IN AL, [09H] Operations: PORTaddr = 09H (AL) (PORT) Content of port with address 09H is moved to AL register In indirect port addressing mode, the instruction will specify the name of the register which holds the port address. In 8086, the 16-bit port address is stored in the DX register. Example: OUT [DX], AX Operations: PORTaddr = (DX) (PORT) (AX) Content of AX is moved to port whose address is specified by DX register. Group III : Addressing modes for I/O ports 20
- 21. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing In this addressing mode, the effective address of a program instruction is specified relative to Instruction Pointer (IP) by an 8-bit signed displacement. Example: JZ 0AH Operations: 000AH 0AH If ZF = 1, then (sign extend) EA = (IP) + 000AH BA = (CS) x 1610 MA = BA + EA If ZF = 1, then the program control jumps to new address calculated above. If ZF = 0, then next instruction of the program is executed. Group IV : Relative Addressing mode 21
- 22. 1. Register Addressing 2. Immediate Addressing 3. Direct Addressing 4. Register Indirect Addressing 5. Based Addressing 6. Indexed Addressing 7. Based Index Addressing 8. String Addressing 9. Direct I/O port Addressing 10. Indirect I/O port Addressing 11. Relative Addressing 12. Implied Addressing Instructions using this mode have no operands. The instruction itself will specify the data to be operated by the instruction. Example: CLC This clears the carry flag to zero. Group IV : Implied Addressing mode 22