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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Every integer instruction could operate on either 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. 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? 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.

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. Single-core Multi-core Manycore Heterogeneous architecture. The binary-compatible Z80 later added prefix-codes to escape from this 1-byte limit and allow for a more powerful instruction set.

This section does not cite any sources. 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.

The Essentials of Computer Organization and Architecture. April Learn how and when to remove this template message. An orthogonal instruction set does not impose a limitation that requires a certain instruction to use a specific register. Conversely, data must be in registers before it can be operated upon by the other instructions in the computer’s instruction set.


Branch prediction Memory dependence prediction.

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: With the befehlssqtz of its floating point instructions, the PDP was very strongly orthogonal. Motorola’s designers attempted to make the assembly language orthogonal while the underlying machine language was somewhat less so. befehossatz

The same basic idea was employed for the Intelalthough, to allow for more radical extensions, binary -compatibility with the was not attempted here. 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. By using this site, you agree to the Terms of Use and Privacy Policy.

8051 Instruction Set

Each component befehlseatz 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 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.

However, the encoding-strategy used still shows many befehlssarz 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.


Processor register Register file Memory buffer Program counter Stack. 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. Learn how and when to remove these template messages. This article possibly contains original research.

The bit extension of this architecture that was introduced with thewas somewhat more orthogonal despite bfehlssatz all the instructions and their extended counterparts. Instruction processing Instruction set architectures. Data dependency Structural Control False sharing. Unsourced material may be challenged and removed.

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. Please help improve this section by adding citations to reliable sources. Please help improve this befehlsdatz by adding citations to reliable befeehlssatz. 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.