|
Z280
The Zilog Z280 is a 16-bit computing, 16-bit microprocessor designed by Zilog as an enhancement of the Zilog Z80 architecture and integrating improvements from the abandoned Zilog Z800 project. First introduced in July 1987, the Z280 is considered to be a commercial failure. The Z280 was fabricated in CMOS, added a memory management unit (MMU) to expand the Address space, addressing range to 16 Megabyte, MB, features for Computer multitasking, multitasking and multiprocessor and coprocessor configurations, and 256 bytes of on-chip static RAM, configurable as either a CPU cache, cache for instructions and/or data, or as part of the ordinary address space. It has a huge number of new instruction (computer science), instructions and addressing modes giving a total of over 2000 combinations. It offers Supervisor and User operating modes, and optionally separate address spaces for instructions and data in both modes (four total possible address spaces). Its crystal or external c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zilog Z80
The Zilog Z80 is an 8-bit computing, 8-bit microprocessor designed by Zilog that played an important role in the evolution of early personal computing. Launched in 1976, it was designed to be Backward compatibility, software-compatible with the Intel 8080, offering a compelling alternative due to its better Integrated circuit, integration and increased performance. Along with the 8080's seven Processor register, registers and flags register, the Z80 introduced an alternate register set, two 16-bit index registers, and additional instructions, including bit manipulation and block copy/search. Originally intended for use in embedded systems like the 8080, the Z80's combination of compatibility, affordability, and superior performance led to widespread adoption in video game systems and home computers throughout the late 1970s and early 1980s, helping to fuel the personal computing revolution. The Z80 was used in iconic products such as the Osborne 1, TRS-80, Radio Shack TRS-80, Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zilog Z800
The Zilog Z800 was a 16-bit microprocessor designed by Zilog and meant to be released in 1985. It was instruction compatible with their existing Z80, and differed primarily in having on-chip cache and a memory management unit (MMU) to provide a 16 MB address range. It also added a huge number of new more orthogonal instructions and addressing modes. Zilog essentially ignored the Z800 in favor of their 32-bit Z80000 and the Z800 never entered mass production. After more than five years had elapsed since it was originally introduced, the effort was redubbed the Z280 in 1986.EDN November 27, 1986, p133 An actual product, the Z280 would ship in 1987 with almost the same design as the Z800, but this time implemented in CMOS. The Z800 contrasts with Zilog's first 16-bit effort, the Zilog Z8000, in that the Z800 was intended to be Z80 compatible, while the Z8000 was only Z80-like and did not offer any direct compatibility. Zilog sought to rectify the lack of Z80 compatibility exhib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STEbus Z280 CPU On 100x160mm Eurocard
The STEbus (also called the IEEE-1000 bus) is a non-proprietary, processor-independent, computer bus with 8 data lines and 20 address lines. It was popular for industrial control systems in the late 1980s and early 1990s before the ubiquitous IBM PC dominated this market. STE stands for STandard Eurocard. Although no longer competitive in its original market, it is valid choice for hobbyists wishing to make 'home brew' computer systems. The Z80 and probably the CMOS 65C02 are possible processors to use. The standardized bus allows hobbyists to interface to each other's designs. Origins In the early 1980s, there were many proprietary bus systems, each with its own strengths and weaknesses. Most had grown in an ad-hoc manner, typically around a particular microprocessor. The S-100 bus is based on Intel 8080 signals, the STD Bus around Z80 signals, the SS-50 bus around the Motorola 6800, and the G64 bus around 6809 signals. This made it harder to interface other proc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EZ80
The Zilog eZ80 is an 8-bit microprocessor designed by Zilog as an updated version of the company's first product, the highly-successful Zilog Z80. The eZ80 is binary compatible with the Z80, but it operates almost three times faster at the same clock frequency. Design The eZ80 has a three-stage pipeline: fetch, decode, and execute. When an instruction changes the program counter, it flushes the instructions that the CPU is currently processing. Available at up to 50 MHz (2004), the performance is comparable to a Z80 clocked at 150 MHz if fast memory is used (i.e. no wait states for opcode fetches, for data, or for I/O) or even higher in some applications (a 16-bit addition is 11 times as fast as in the original). The original Z80-compatible 16-bit register configuration is supported. The eZ80 also supports direct continuous addressing of 16 MB of memory without a memory management unit, by extending most registers (HL, BC, DE, IX, IY, SP, and PC) from 16 to 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
16-bit Computing
16-bit microcomputers are microcomputers that use 16-bit microprocessors. A 16-bit register can store 216 different values. The range of integer values that can be stored in 16 bits depends on the integer representation used. With the two most common representations, the range is 0 through 65,535 (216 − 1) for representation as an ( unsigned) binary number, and −32,768 (−1 × 215) through 32,767 (215 − 1) for representation as two's complement. Since 216 is 65,536, a processor with 16-bit memory addresses can directly access 64 KB (65,536 bytes) of byte-addressable memory. If a system uses segmentation with 16-bit segment offsets, more can be accessed. As of 2025, 16-bit microcontrollers cost well under a dollar (similar to close in price legacy 8-bit); the cheapest 16-bit microcontrollers cost less than other types including any 8-bit (and are more powerful, and easier to program generally), making 8-bit legacy microcontrollers not worth it for new applications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zilog
Zilog, Inc. is an American manufacturer of microprocessors, microcontrollers, and application-specific embedded System on a chip, system-on-chip (SoC) products. The company was founded in 1974 by Federico Faggin and Ralph Ungermann, who were soon joined by Masatoshi Shima. All three had left Intel after working on the Intel 4004, 4004 and Intel 8080, 8080 microprocessors. The company's most famous product is the Zilog Z80, Z80 microprocessor, which played an important role in the evolution of early computing. Backward compatible, Software-compatible with the Intel 8080, it offered a compelling alternative due to its lower cost and increased performance, propelling it to widespread adoption in video game systems and home computers during the late 1970s and early 1980s. The name, pronounced with a long "i" (), is an acronym of ''Z integrated logic'', also thought of as "Z for the last word of Integrated Logic". History Zilog was started in California in 1974 by Federico Faggin and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Pipelining
In computer engineering, instruction pipelining is a technique for implementing instruction-level parallelism within a single processor. Pipelining attempts to keep every part of the processor busy with some instruction by dividing incoming instructions into a series of sequential steps (the eponymous "pipeline") performed by different processor units with different parts of instructions processed in parallel. Concept and motivation In a pipelined computer, instructions flow through the central processing unit (CPU) in stages. For example, it might have one stage for each step of the von Neumann cycle: Fetch the instruction, fetch the operands, do the instruction, write the results. A pipelined computer usually has "pipeline registers" after each stage. These store information from the instruction and calculations so that the logic gates of the next stage can do the next step. This arrangement lets the CPU complete an instruction on each clock cycle. It is common for even-nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Management Unit
A memory management unit (MMU), sometimes called paged memory management unit (PMMU), is a computer hardware unit that examines all references to computer memory, memory, and translates the memory addresses being referenced, known as virtual memory addresses, into physical addresses in main memory. In modern systems, programs generally have addresses that access the theoretical maximum memory of the computer architecture, 32 or 64 bits. The MMU maps the addresses from each program into separate areas in physical memory, which is generally much smaller than the theoretical maximum. This is possible because programs rarely use large amounts of memory at any one time. Most modern operating systems (OS) work in concert with an MMU to provide virtual memory (VM) support. The MMU tracks memory use in fixed-size blocks known as ''pages''. If a program refers to a location in a page that is not in physical memory, the MMU sends an interrupt to the operating system. The OS selects a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trap (computing)
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an ''interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking and system calls, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. History Hardware interrupts were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Protection
Memory protection is a way to control memory access rights on a computer, and is a part of most modern instruction set architectures and operating systems. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself. Protection may encompass all accesses to a specified area of memory, write accesses, or attempts to execute the contents of the area. An attempt to access unauthorized memory results in a hardware fault, e.g., a segmentation fault, storage violation exception, generally causing abnormal termination of the offending process. Memory protection for computer security includes additional techniques such as address space layout randomization and executable-space protection. Methods Segmentation Segmentation refers to dividing a computer's memory into segments. A reference to a memory locatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Memory Allocation
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system performance. The system allows a computer to appear as if it may have more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
