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, #.
|Genre:||Health and Food|
|Published (Last):||3 November 2011|
|PDF File Size:||6.68 Mb|
|ePub File Size:||15.58 Mb|
|Price:||Free* [*Free Regsitration Required]|
Motorola’s designers attempted to make the assembly language orthogonal while the underlying machine language was somewhat less so. 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.
Orthogonal instruction set
Statements consisting becehlssatz of original research should be removed. 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 exploited for code optimization in both compilers and hand written code.
Designers of RISC architectures strove to achieve a balance that they thought better.
Orthogonal instruction set – Wikipedia
Unlike PDP, the MC used separate registers to store data and the addresses of data in memory. Since the PDP was an octal-oriented 3-bit sub-byte machine addressing modes 0—7, registers R0—R7there were electronically 8 addressing modes.
Views Read Edit View history.
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? Through the use of the Stack Pointer R6 and Program Counter R7 as referenceable registers, there were 10 conceptual addressing modes available.
8051 Microcontroller Instruction Set
Bbefehlssatz integer instruction could operate on either 1-byte or 2-byte integers and befeh,ssatz access data stored in registers, stored as part of the instruction, stored in memory, or stored in memory and pointed to by addresses in registers.
Each component being one bytethe opcode a value in the range 0—, and each operand consisting of two nibblesthe upper 4 bits specifying an addressing mode, and the lower 4 bits usually specifying a register number R0—R 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.
Even the PC and the stack pointer could be affected by the ordinary instructions using all of the ordinary data modes. It is ” orthogonal ” in the sense that the instruction type and the addressing mode vary independently. The Essentials of Computer Organization and Architecture. An assembly-language programmer or compiler writer had to be mindful of which operations were possible on each register: In these architectures, only a very few memory reference instructions can access main memory and only for the purpose of loading data into registers or storing register data back into main memory; only a few addressing modes may be available, and these modes may vary depending on whether the instruction refers to data or involves a transfer of control jump.
Tomasulo algorithm Reservation station Re-order buffer Register renaming. Please improve it by verifying the claims made and adding inline citations. Single-core Multi-core Manycore Heterogeneous architecture. This article has multiple issues.
Learn how and when to remove these template messages. The same basic idea was employed for the Intelalthough, to allow for more radical extensions, binary -compatibility with the was not attempted here. Branch prediction Memory dependence prediction. The binary-compatible Z80 later added prefix-codes to escape from this 1-byte limit and allow for a more powerful instruction set. This article possibly contains original research.
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.
Retrieved from ” https: The bit extension of this architecture that was introduced with thewas somewhat more orthogonal despite keeping all the instructions and their extended counterparts.
This trade off is made explicitly to enable the use of much larger register befehlssqtz, extended virtual addresses, and longer immediate data data stored directly within the computer instruction. This section does not cite any sources. From Wikipedia, the free encyclopedia.
The 8-bit Intel as well as the and microprocessor was basically a slightly extended accumulator-based design and therefore not orthogonal.
Please help improve this article by adding citations to reliable sources.
Please help improve this section by adding citations to reliable sources. This was largely due to a desire to keep all opcodes one byte long. An orthogonal instruction set does not impose a limitation that requires a certain instruction to use a specific register. With the befehlssazt of its floating point instructions, the PDP was very strongly orthogonal.
Please help improve it or discuss these issues befeehlssatz the talk page. 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.
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.
Articles that may contain original research from November All befehlsatz that may contain original research Articles needing additional references from April All articles needing additional references Articles with multiple maintenance issues Articles needing additional references from April All articles with specifically marked weasel-worded phrases Articles with specifically marked weasel-worded phrases from April Conversely, data must beehlssatz in registers before it can be operated upon by the other instructions in the computer’s instruction set.
This article needs additional citations for verification.
Instruction Set Manual: Opcodes
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. In many CISC computers, an instruction could access either registers befehlesatz memory, usually in several different ways.
Processor register Register file Memory buffer Program counter Stack. April Learn how and when to remove this template message. A fully orthogonal architecture may not be the most “bit efficient” architecture.