Harvard structure and von noriman Structure

1. Harvard structure and its main features:

The Harvard structure is a memory structure. The Harvard-structured processors include AVR, arm9, arm10, and arm11. At present, there are a lot of central processors and controllers that use the Harvard structure, except for the PIC chips of the microchip company, there are also the mc68 series of Motorola, Z8 series of zilog, AVR series of ATMEL, and arm10, arm11 of Amou.

The Harvard structure is a memory structure that separates program instruction storage from data storage. The Harvard structure is a parallel architecture. Its main feature is to store programs and data in different buckets, that is, the program memory and data storage are two independent memories, each memory is independently edited and accessed. What corresponds to the two storages is the four bus of the system: the program data bus and the address bus, the data bus and the address bus. This separation of the program bus and Data Bus allows the simultaneous acquisition of commands (from program memory) and operands (from data storage) within a machine cycle, thus improving the execution speed, this improves the data throughput. Because the program and data are stored in two separate physical spaces, the addressing and execution can overlap completely. The central processor first reads the content of the program instruction in the program instruction memory, decodes the content, obtains the data address, reads the data in the corresponding data storage, and performs the next operation (usually execution ). The program instruction storage and data storage are separated, so that the instruction and data have different data widths.

Computers in Harvard structure are composed of CPUs, program memory and data storage. program memory and data storage use different bus, thus providing a large memory bandwidth, this makes data movement and exchange more convenient, especially providing high digital signal processing performance.

2. Von noriman Structure

The Princeton structure is a memory structure that combines program instruction memory and data storage. The program instruction storage address and data storage address point to different physical locations of the same storage, so the program instruction and data width are the same, for example, Intel's 8086 central processor's program commands and data are both 16-bit wide.

Consists of five parts, including: memory, logical control device, memory, input and output device

One of the design ideas is binary. It is recommended to use binary in electronic computers based on the characteristics of the electronic component's bistability. The report mentions the advantages of binary and predicts that the adoption of binary will greatly simplify the logic line of the machine.

At present, there are many central processors and controllers that use the Von noriman structure. In addition to the intel 8086 mentioned above, Intel's other central processor, Amou's ARM7 and MIPS's MIPS processor also adopt the Von noriman structure.

3. Comparison between Harvard structure and von noriman structure:

Compared with the Von noriman structure processor, the Harvard structure processor has two obvious features: two independent memory modules are used to store commands and data respectively, and each storage module does not allow the coexistence of commands and data; the two independent bus are used as the dedicated communication path between the CPU and each memory, and there is no association between the two bus.