Bare Metal: Baud rate and bit rate

Using the serial port often see the term baud rate, often based on it to adjust the serial port clock.

However, the baud rate is not strictly reflect the serial port transmission rate (clock frequency), in fact, the bit rate can directly reflect the signal transmission rate (clock frequency), Baidu found the answer:

Bit rate:

The amount of information transmitted through the channel per second is called the bit transfer rate, which is the number of bits transmitted per second, or bit rate. Bit rate indicates the transfer rate of valid data, with B/s, bit/s, bit/sec, read: bits per second.

Baud rate

The baud rate reflects the number of data elements transmitted per second. For example, the common serial port, the data is usually transmitted through such a frame: 1bit starting bit (0) + 8bit data bit + 1bit end bit (1). the data element here is byte (8bit data), if our serial baud rate is 115200, it means we can transmit 115,200 bytes per second.

The bit rate should be 115200* 10 at this time.

The unit "baud" itself is already representing the number of modulation per second, with "baud per second" (Baud per second) unit is a common error.

The relationship between baud rate and bit rate can also be converted to: bit rate = Baud rate * The number of bits for a single modulation state.

Bare Metal: Baud rate and bit rate