Microcontroller Instruction Set. For interrupt response time information, refer to the hardware description chapter. Note: 1. Operations on SFR byte address Instruction Set. ♢ Introduction. ♢ CIP architecture and memory organization review. ♢ Addressing modes. ➢ Register addressing. ➢ Direct addressing. Instruction hex code. MOVE with immediate data. Hex. Bytes Instruction. 2. MOV A, #immediate. 3. MOV direct, #immediate. 2. MOV @R0, #.
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This article has multiple issues. Tomasulo algorithm Reservation station Re-order buffer Register renaming. The Essentials of Computer Organization and Architecture.
It is ” orthogonal ” in the sense that the instruction type and the addressing mode vary independently. This compromise gave almost the same convenience as a truly orthogonal machine, and yet also gave the CPU designers freedom to use the bits in the instructions more efficiently than a purely orthogonal approach might have.
Please help improve this article by adding citations to befehslsatz sources. However, the encoding-strategy used still shows many traces from the and and Z80 ; for instance, single-byte encodings remain for certain frequent operations such as push and pop of registers and constants, and the primary accumulator, eaxemploy shorter encodings than the other registers on certain types of operations; observations like this are sometimes 80551 for code optimization in both compilers and hand written code.
This resulted in 16 logical addressing modes 0—15however, addressing modes 0—3 were “short immediate” for immediate data of 6 bits or less the 2 low-order bits of the addressing mode being the 2 high-order bits of the immediate data, when prepended to the remaining 4 bits in that data-addressing byte.
This section does not cite any sources. Perhaps some of the bits that were used to express the fully orthogonal instruction set could instead be used to express more virtual address bits or select from among more registers.
In these architectures, only a very few memory reference instructions can access main memory and only for the purpose of loading data into registers befehlssstz storing register data back into main memory; only a few addressing modes may be available, and these modes may bffehlssatz depending on whether the instruction refers to data or involves a transfer of control jump. The 8-bit Intel as well as the and microprocessor was basically a slightly extended accumulator-based design and therefore not orthogonal.
Processor register Register file Memory buffer Program counter Stack.
Orthogonal instruction set
From Wikipedia, the free encyclopedia. Conversely, data must be in registers before it can be operated upon by the other instructions in the computer’s instruction set. Please improve it by verifying the claims made and adding inline citations. In many CISC computers, an instruction could access either registers or memory, usually in several different ways.
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An orthogonal instruction set does not impose a limitation that requires a certain instruction to use a specific register. April Learn how and when to remove this template message.
Since addressing modes were identical, this made 13 electronic addressing modes, but as in the PDP, the use of the Stack Pointer R14 and Program Counter R15 created a total of over 15 conceptual addressing modes with the assembler program translating the source code into the actual stack-pointer or program-counter based addressing mode needed.
At the bit level, the person writing the assembler or debugging machine code would clearly see that symbolic instructions could become any of several different op-codes.
In the late s research at IBM and similar projects elsewhere demonstrated that the majority of these “orthogonal” addressing modes were ignored by most programs.
8051 Instruction Set
This article possibly contains original research. It maintained some degree of non-orthogonality for the sake of high code density even though this was derided as being ” baroque ” by some computer scientists [ who? Data dependency Structural Control False sharing.
An assembly-language programmer or compiler writer had to be mindful of which operations were possible on each register: Views Read Edit View history. This page was last edited on 10 Augustat Unsourced material may be challenged and removed. This trade off is made explicitly to enable the use of much larger register sets, extended virtual addresses, and longer immediate data data stored directly within the computer instruction.
This was largely due to a desire to keep all opcodes one byte long. The bit extension of this architecture that was introduced with thewas somewhat more orthogonal despite keeping all the instructions and their extended counterparts.
Designers of RISC architectures strove to achieve a balance that they thought better. Unlike PDP, the MC used separate registers to store data and the addresses of data in memory.