UART serial communication method based on gpio handshake and edma

Abstract

The invention discloses a UART (universal asynchronous receiver / transmitter) serial port communication method based on GPIO (general purpose input / output) handshake and EDMA (enhanced direct memory access). According to the method, data migration from transmitting and receiving FIFO of UART to an external data buffer is completed automatically on the basis of an EDMA function, and frequent intervention of CPU (central processing unit) is not needed; a receiving terminal is informed through GPIO handshake signals to receive data packets, and the boundaries of the received data packets can be rapidly distinguished and an address of a next to-be-received data packet can be automatically updated; therefore, the efficiency of communication adopting UART serial ports is greatly improved, frequent interruption to CPU processing is reduced when the UART transmits and receives the data pockets, and the utilization rate of CPU resources can be increased. Meanwhile, according to the scheme, the GPIO signals are utilized to have an appointment with opposite terminal equipment, and convenience produced when the opposite terminal equipment uses the UART for receiving is improved to a certain degree, so that the work efficiency of communication adopting the UART serial ports is improved at the level of the overall system.

Description

technical field [0001] The invention relates to the field of serial port communication, in particular to a UART serial port communication method based on GPIO handshake and EDMA. Background technique [0002] UART is the abbreviation of Universal Asynchronous Receiver / Transmitter, that is, universal asynchronous receiving and sending. When it is used as the sending side of DSP, it can convert the parallel data to be sent by DSP into serial data and send it to the peripheral device of DSP. When it is used as DSP On the receiving side, the serial data sent by the DSP peripheral can be converted into parallel data and received. Because the UART hardware connection is simple and the communication protocol is easy to implement, it is widely used in embedded systems and industrial control systems. But the traditional serial port protocol has two defects: [0003] 1. Only one data symbol (5 to 8 data bits) is sent and received each time. If the CPU is required to intervene in pro...

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Problems solved by technology

[0003] 1. Only one data symbol (5 to 8 data bits) is sent and received at a time. If CPU intervention is required for each data symbol, the efficiency is very low

[0004] 2. When using the serial port for burst data packet transmission, the serial port communication protocol itself does not stipulate how to divide the boundary of the data packet, and it is necessary to realize the boundary of the data packet by itself

[0006] 1. The DSP device using this technology must have a virtual port and a virtual FIFO controller

[0007] 2. The cache FIFO must be located in the address of the peripheral components, and the memory locations such as L2 and DDR of the DSP cannot be flexibly used

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