Baud rate correction hardware device for serial data transmission and design method

Abstract

The invention discloses a Baud rate correction hardware device for serial data transmission. The device comprises a data bus, a high-speed crystal oscillator, a Baud rate signal generator, a transmitting and receiving control circuit, an RC frequency test adjusting circuit, a Baud rate calibration circuit and a Baud rate signal and calibration signal mixer; the baud rate signal generator is connected with the high-speed crystal oscillator, the baud rate signal and calibration signal mixer and the data bus, and the RC frequency test adjusting circuit is respectively connected with the high-speed crystal oscillator and the baud rate calibration circuit; the baud rate signal and calibration signal mixer is connected with the baud rate calibration circuit and the transmitting and receiving control circuit. According to the invention, an existing low-frequency crystal rate oscillator of a timing product is adopted, internal oscillators of most single-chip microcomputer products are combined, and innovative Baud rate correction hardware design is used, so a stable high-Baud rate asynchronous serial communication function is realized.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a baud rate correction hardware device and design method for serial data transmission. Background technique [0002] The baud rate is a parameter to measure the communication speed. It indicates the number of bits transmitted per second. The device connected to the serial port communicates at the agreed baud rate, that is, the devices at both ends of the serial port only have the condition of maintaining the same rate. Normal communication can be realized only under this condition, otherwise the debugging command will be invalid and garbled characters will be displayed. Under normal circumstances, the digital circuit inside the serial port chip usually has a counter that uses a high-frequency clock. After receiving the start bit, the counter starts to count cyclically. When the counter counts to n / 2, the receiving end saves the sampled sending end. In practical applicatio...

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Problems solved by technology

[0004] In the types of electronic products with timing function, considering the frequency accuracy and low-frequency power-saving characteristics, low-frequency oscillators will be selected as the timing clock source, such as 32768hz crystal oscillators, but if the same project requires higher For asynchronous serial communication with baud rate, it is necessary to add another high-frequency crystal oscillator. Usually, 11.0592MHz or 5.5296MHz is selected. The disadvantage of this conventional method is that it increases the cost, and on the other hand Due to the use of higher oscillation frequency, it has a bad influence on the minimum working voltage of the product

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