How fast is serial

A serial frame. Some symbols in the frame have configurable bit sizes. The real meat of every serial packet is the data it carries. We ambiguously call this block of data a chunk , because its size isn't specifically stated. The amount of data in each packet can be set to anything from 5 to 9 bits. Certainly, the standard data size is your basic 8-bit byte, but other sizes have their uses. A 7-bit data chunk can be more efficient than 8, especially if you're just transferring 7-bit ASCII characters.

After agreeing on a character-length, both serial devices also have to agree on the endianness of their data. Is data sent most-significant bit msb to least, or vice-versa? If it's not otherwise stated, you can usually assume that data is transferred least-significant bit lsb first.

The synchronization bits are two or three special bits transferred with each chunk of data. They are the start bit and the stop bit s.

True to their name, these bits mark the beginning and end of a packet. There's always only one start bit, but the number of stop bits is configurable to either one or two though it's commonly left at one. The start bit is always indicated by an idle data line going from 1 to 0, while the stop bit s will transition back to the idle state by holding the line at 1.

Parity is a form of very simple, low-level error checking. It comes in two flavors: odd or even. To produce the parity bit, all bits of the data byte are added up, and the evenness of the sum decides whether the bit is set or not. For example, assuming parity is set to even and was being added to a data byte like 0b , which has an odd number of 1 's 5 , the parity bit would be set to 1.

Conversely, if the parity mode was set to odd, the parity bit would be 0. I know that the specification says it is bps. But i believe it can be faster. What influences the speed of the rs port? I believe it is quartz resonator but i am not sure. The engineers that designed it needed a cheap way to generate a stable frequency.

A crystal made to run an oscillator circuit at the color burst frequency in the NTSC television standard. From there, it first went through a programmable divider, the one you change to set the baudrate. The UART itself then divides it by 16 to generate the sub-sampling clock for the data line. So the highest baudrate you can get is by setting the divider to the smallest value, 2. But close enough, the clock rate doesn't have to be exact. The point of asynchronous signalling, the A in UART, the start bit always re-synchronizes the receiver.

Getting real RS hardware running at baud reliably is a significant challenge. The electrical standard is very sensitive to noise, there is no attempt at canceling induced noise and no attempt at creating an impedance-matched transmission line.

The maximum recommended cable length at baud is only 50 feet. At only very short cables will do in practice. To go further you need a different approach, like RS's differential signals. This is all ancient history and doesn't exactly apply to modern hardware anymore. Which have a custom driver to emulate a serial port. They do accept a baudrate selection but just ignore it for the USB bus itself, it only applies to the last half-inch in the dongle you plug in the device.

Whether or not the driver accepts as the maximum value is a driver implementation detail, they usually accept higher values.

If you use a USB-based serial adapter, there's no involved and the limit is instead set by the specific chip s used in the adapter, of course. In response to the comment about clocking with a caveat: I'm a software guy : asynchronous serial communication doesn't transmit the clock that's the asynchronous part right there along with the data.

An asynchronous port on the computer used to connect a serial device to the computer and capable of transmitting one bit at a time. The serial port is a type of connection on PCs that is used for peripherals such as mice, gaming controllers, modems, and older printers. Most newer computers have replaced serial ports with much faster and more compatible USB ports. Parallel communication devices are faster than their serial counterparts.

A serial communication device sends data in bits, and at the end the bits harmonize to form a byte of data. A parallel communication device sends and receives the same amount of data simultaneously, thus making it faster. Serial ports usually connect devices that do not require fast data transmission rates, such as a mouse, keyboard , or modem.

A parallel port is an interface that connects devices by transferring more than one bit at a time. In computer networking, a serial port enables external modems to connect to a PC or network router via a serial cable. The term " serial " signifies that data sent in one direction always travels over a single wire within the cable.

A parallel port is able to transmit multiple data streams at a time. A serial port sends data bit by bit after sending a bit at a time. A parallel port sends data by sending multiple bits in parallel fashion. A serial port uses Male ports. Definition - What does Parallel Port mean? A parallel port is an interface allowing a personal computer PC to transmit or receive data down multiple bundled cables to a peripheral device such as a printer.

The most common parallel port is a printer port known as the Centronics port. Wireless signals are transmitted in a duplex form, meaning both sides can talk at the same time.

Just like when you're in front of someone, talking to them, your speech isn't transmitted in a serial or parallel way. What is the speed of serial port? Category: technology and computing computer peripherals. The speed of the serial link in bits per second. The Linux kernel on a modern PC supports a serial console speeds of , , , , , , and bits per second.