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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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. Conversely, data must be in registers before it can be operated upon by the other instructions in the computer’s instruction set.
The bit extension of this architecture that was introduced with thewas somewhat more orthogonal despite keeping all the instructions and their extended counterparts.
8051 Instruction Set
An orthogonal instruction set does not impose befehlsswtz limitation that requires a certain instruction to use a specific register. Every integer instruction could operate on befeglssatz 1-byte or 2-byte integers and could 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.
Orthogonal instruction set – Wikipedia
Befehhlssatz of RISC architectures strove to achieve a balance that they thought better. Perhaps some of the bits that befehlssxtz used to express the fully orthogonal instruction set could instead be used to express more virtual address bits or select from among more registers.
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?
Please help improve it or discuss these issues on the talk page. Unlike PDP, the MC used separate registers to store data and the addresses of data in memory. Articles that may contain original research from November All articles 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 80051 articles with specifically marked weasel-worded phrases Articles with specifically marked weasel-worded phrases from April Befehlsastz register Register file Memory buffer Program counter Stack.
Please help improve this article by adding citations to reliable sources. This compromise gave almost the same convenience as a truly orthogonal machine, befehlssatx yet also gave the CPU designers freedom to use the bits in the instructions more efficiently than a purely orthogonal approach might have.
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.
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Branch prediction Memory dependence prediction. Data dependency Structural Control False sharing. Even the PC and the stack pointer could be affected by the ordinary instructions using all of the ordinary data modes. Through the use of 801 Stack Pointer R6 and Program Counter R7 as referenceable registers, there were 10 conceptual addressing modes available.
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 befehlssatz, when prepended to the remaining 4 bits in that data-addressing byte. 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 Since the PDP was an octal-oriented 3-bit sub-byte machine addressing modes 0—7, registers R0—R7there were electronically 8 addressing modes.
The 8-bit Intel as well as the and microprocessor was basically a slightly extended accumulator-based design and therefore not orthogonal.
The binary-compatible Z80 later added prefix-codes to escape from befehlsatz 1-byte limit and allow for a more powerful instruction set. This article needs additional citations for verification.
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. November Learn how and when to remove this template message.
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