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The Intel 8085 ("eighty-eighty-five") is an 8-bit microprocessor produced by Intel and introduced in March 1976. [2] It is the last 8-bit microprocessor developed by Intel. It is software-binary compatible with the more-famous Intel 8080 with only two minor instructions added to support its added interrupt and serial input/output features.
Memory-mapped I/O is preferred in IA-32 and x86-64 based architectures because the instructions that perform port-based I/O are limited to one register: EAX, AX, and AL are the only registers that data can be moved into or out of, and either a byte-sized immediate value in the instruction or a value in register DX determines which port is the source or destination port of the transfer.
In virtual memory implementations and memory management units, a memory map refers to page tables or hardware registers, which store the mapping between a certain process's virtual memory layout and how that space relates to physical memory addresses. In native debugger programs, a memory map refers to the mapping between loaded executable(or ...
Memory-mapped file, also known as mmap() Memory-mapped I/O, an alternative to port I/O; a communication between CPU and peripheral device using the same instructions, and same bus, as between CPU and memory; Virtual memory, technique which gives an application program the impression that it has contiguous working memory, while in fact it is ...
The instruction set architecture (ISA) that the computer final version (SAP-3) is designed to implement is patterned after and upward compatible with the ISA of the Intel 8080/8085 microprocessor family. Therefore, the instructions implemented in the three SAP computer variations are, in each case, a subset of the 8080/8085 instructions.
In a system using segmentation, computer memory addresses consist of a segment id and an offset within the segment. [3] A hardware memory management unit (MMU) is responsible for translating the segment and offset into a physical address, and for performing checks to make sure the translation can be done and that the reference to that segment and offset is permitted.
Store to memory using Direct Store (memory store that is not cached or write-combined with other stores). 3 Tiger Lake, Tremont, Zen 5: MOVDIR64B Move 64 bytes as Direct Store. MOVDIR64B reg,m512: 66 0F 38 F8 /r: Move 64 bytes of data from m512 to address given by ES:reg. The 64-byte write is done atomically with Direct Store. [ah] 3 Tiger Lake ...
In contrast, in direct memory access (DMA) operations, the CPU is uninvolved in the data transfer. The term can refer to either memory-mapped I/O (MMIO) or port-mapped I/O (PMIO). PMIO refers to transfers using a special address space outside of normal memory, usually accessed with dedicated instructions, such as IN and OUT in x86 architectures.