串行与平行传输
The primary difference between serial and parallel transmission is in the way the data is transmitted. In serial transmission it is sequential whereas, in parallel transmission, it its simultaneous. In the computer world, data is transmitted digitally usingbits。在串行传输中,数据是按顺序发送的,其中一位通过单线发送了另一个位。在并行传输中,数据并行发送,其中使用多条电线同时传输了几个位。由于我们在下面讨论的各种原因,串行传输比平行传输具有更多的优势,因此,在大多数使用的接口(例如)USB,SATAand PCI Express.
What is Serial Transmission?
串行传输是指transmission of one bit at a timewhere the传输是顺序的。Say we have a byte of data “10101010” to be sent over a serial transmission channel. It sends bit by bit one after the other. First “1” is sent and then “0” is sent, again “1” and so on. So, essentially, only one data line/wire is needed for transmission and it is an advantage when cost is considered. Today, many transmission technologies use serial transmission as it has several advantages. One important advantage is the fact that because there are no parallel bits there is no need for synchronization. In that case, clock speed can be increased up to a very high level that a great波特率can be achieved. Also, due to the same reason,it is possible to use serial transmission for long distance without any issue. Also, since there are no nearby parallel lines, the signal is not affected by phenomena such as cross talk and interference from the neighboring lines, as what happens in parallel transmission.
The term serial transmission is very much linked withRS-232这是很久以前在IBM PC中引入的串行通信标准。它使用串行传输,也称为serial port。USB (Universal Serial Bus), which is the most widely used interface today in the computer industry, is also serial.以太网, which we use for connecting networks, also follows serial communication. SATA (Serial Advanced Technology Attachment), which is used to fixhard disks和光盘的读者,也连续name itself suggests. Other well-known serial transmission technologies include Fire wire, RS-485, I2C, SPI (Serial Peripheral Interface), MIDI (Musical Instrument Digital Interface). Moreover, PS/2, which was used for connecting mouses and keyboards, was also serial. Most importantly, PCI Express, which is used to connect modern graphics cards to the PC also follows serial transmission.
What is Parallel Transmission?
Parallel transmission refers to并行数据位同时传输。假设我们有一个平行的传输系统,一次发送8位。它应由8条单独的线/电线组成。想象一下,我们想通过并联传输传输数据字节“ 10101010”。在这里,第一行发送“ 1”,第二行发送“ 0”,依此类推。每行都会同时发送与它相对应的位。缺点是应该有多个电线,因此成本很高。同样,由于应该有更多的引脚,因此端口和插槽变得更大,使其不适合小型嵌入式设备。在谈论并行传输时,首先想到的是,平行变速器应该更快,因为同时进行了几个位。从理论上讲,这一定是如此,但是由于实际原因,平行传输甚至比串行传输慢。 The reason is all parallel data bits must be received at the receiver’s end before the next data set is sent. However, the signal on different wires can take different times and hence all bits are not received at the same time and therefore for synchronization there should be a waiting period. Because of this the clock speed cannot be increased as high as in serial transmission and hence the speed of parallel transmission is slower. Another disadvantage of parallel transmission is that the neighboring wires introduce problems such as cross-talk and interference to each other degrading the signals. Because of these reasons, parallel transmission is used for short distances.
The most famous parallel transmission is the printer port, which is also known as IEEE 1284. This is the port that is also known as the parallel port. This was used for printers, but today, it is not widely used. In the past, hard disks and optical disks readers were connected to the PC using PATA (Parallel Advanced Technology Attachment). As we know, these ports are no longer in use as they have been replaced with serial transmission technologies. SCSI (Small Computer System Interface) and GPIB (General Purpose Interface Bus) are also notable interfaces used in the industry that used parallel transmission.
但是,非常重要的是要知道计算机中最快的巴士,即连接的前侧总线CPU and the RAM, is a parallel transmission.
What is the difference between Serial and Parallel Transmission?
•在串行传输中,数据又一次传输。传输是顺序的。在并行传输中,同时传输了几个位,因此同时进行。
•串行传输只需要一根电线,但是并行传输需要几根电线。
•串行总线的尺寸通常小于平行总线,因为引脚的数量较小。
•串行传输线不会面临干扰和交叉聊天问题,因为附近没有线路,但是由于其附近的线路,并行传输面临此类问题。
•通过increa串行传输可以更快sing the clock rate to very high values. However, in parallel transmission, in order to synchronize the complete receive of all bits, clock rate must be kept slower and hence parallel transmission is generally slower than serial transmission.
• Serial transmission lines can transmit data to a very long distance while it is not so in parallel transmission.
•如今,最广泛使用的传输技术是串行传输。
Summary:
Parallel vs Serial Transmission
如今,串行传输的使用远远超过计算机行业中的平行传输。原因是串行传输可以以非常低的成本传输到远距离,其速度非常快。重要的区别是,串行传输涉及一次仅发送一位,而并行传输涉及同时发送几个位。串行传输因此只需要一根电线,而平行传输需要多条线。USB,以太网,SATA,PCI Express是使用串行传输的示例。如今并未广泛使用并行传输,但在过去的打印机端口和Pata中被使用。
图像提供:
- Serial cablevia Wikicommons (Public Domain)
- IEEE 1284via Wikicommons (Public Domain)
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