Difference between revisions of "Instructions"
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=Overview= | =Overview= | ||
| + | An instruction can be split into 2 parts, the command to use and the data to use for the command. | ||
| − | https://www.youtube.com/watch?v=2h3hQCV3YcE&index=117&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho | + | <youtube>https://www.youtube.com/watch?v=2h3hQCV3YcE&index=117&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho</youtube> |
https://www.youtube.com/watch?v=2h3hQCV3YcE&index=117&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho | https://www.youtube.com/watch?v=2h3hQCV3YcE&index=117&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho | ||
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The data to be used by the OpCode, this can be data eg #21 (ie the number 21) or it can be an address eg 21 (ie memory location 21) | The data to be used by the OpCode, this can be data eg #21 (ie the number 21) or it can be an address eg 21 (ie memory location 21) | ||
| + | |||
| + | =Instruction Set= | ||
| + | Different architectures have a different set of available instructions. For example portable devices tend to use ARM embedded architecture, which has an instruction set similar to the assembly language syntax used by AQA. 32bit Windows/Linux machines use the X86 architecture and instruction set were as 64bit Windows/Linux machines use the X64 architecture and instruction set. | ||
| + | |||
| + | =Addressing= | ||
| + | <youtube>https://www.youtube.com/watch?v=yKNrFfVdu3g&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho&index=120</youtube> | ||
| + | |||
| + | https://www.youtube.com/watch?v=yKNrFfVdu3g&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho&index=120 | ||
===Immediate Addressing=== | ===Immediate Addressing=== | ||
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===Direct Addressing=== | ===Direct Addressing=== | ||
The operand is a location eg 21 | The operand is a location eg 21 | ||
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| + | ===Indirect Addressing - not in AQA Specification=== | ||
| + | The operand is a location which contains the location for the instruction | ||
| + | |||
| + | ===Index Addressing - not in AQA Specification=== | ||
| + | The operand is the number in the Index Regisiter after the location in the instruction | ||
Latest revision as of 09:53, 11 June 2018
Contents
Overview
An instruction can be split into 2 parts, the command to use and the data to use for the command.
https://www.youtube.com/watch?v=2h3hQCV3YcE&index=117&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho
OpCode
The command for the instruction, ie Load, Store, Add
Operand
The data to be used by the OpCode, this can be data eg #21 (ie the number 21) or it can be an address eg 21 (ie memory location 21)
Instruction Set
Different architectures have a different set of available instructions. For example portable devices tend to use ARM embedded architecture, which has an instruction set similar to the assembly language syntax used by AQA. 32bit Windows/Linux machines use the X86 architecture and instruction set were as 64bit Windows/Linux machines use the X64 architecture and instruction set.
Addressing
https://www.youtube.com/watch?v=yKNrFfVdu3g&list=PLCiOXwirraUDUYF_qDYcZV8Hce8dsE_Ho&index=120
Immediate Addressing
The operand is data eg #21
Direct Addressing
The operand is a location eg 21
Indirect Addressing - not in AQA Specification
The operand is a location which contains the location for the instruction
Index Addressing - not in AQA Specification
The operand is the number in the Index Regisiter after the location in the instruction
