微处理机系统第十章MSP430的USCI模组USCI简介UART.ppt

* * * * * * * * * * * * 微處理機系統 第十章MSP430的USCI模組 USCI簡介 UART A Universal Asynchronous Receiver/Transmitter, abbreviated UART, is a type of asynchronous receiver/transmitter, a piece of computer hardware that translates data between parallel and serial forms. UARTs are commonly used in conjunction with communication standards such as EIA, RS-232, RS-422 or RS-485. The universal designation indicates that the data format and transmission speeds are configurable and that the actual electric signaling levels and methods (such as differential signaling etc.) typically are handled by a special driver circuit external to the UART. -from Wiki /wiki/Universal_asynchronous_receiver/transmitter UART The Universal Asynchronous Receiver/Transmitter (UART) takes bytes of data and transmits the individual bits in a sequential fashion. At the destination, a second UART re-assembles the bits into complete bytes. Each UART contains a shift register, which is the fundamental method of conversion between serial and parallel forms. Serial transmission of digital information (bits) through a single wire or other medium is much more cost effective than parallel transmission through multiple wires. -from Wiki /wiki/Universal_asynchronous_receiver/transmitter UART in MSP430 UART Mode UART in MSP430 UART通訊 UART01.C 以示波器觀察Tx訊號變化 UART01.C 0x01 0x03 0x05 0x50 0x80 Why?? UART02.C 由Rx接收資料 兩個人一組，一位執行UART_01發送資料，另一位執行UART_02接收資料觀察UCA0RXBUF或value的值 UART_01 (Transmitter) Tx- Rx- GND- UART_02 (Receiver) -Rx -Tx -GND 上述哪一條線可拿掉而不影響結果??Why? UART03.C Rx之中斷(Interrupt) 如左圖設定觀察點，將Tx連接至自己的Rx，觀察程式進行及value值的變化 UART_03 Tx- Rx- GND- UART04.C 與PC連結 以麵包板完成所需電路 MSP430 Rx(P1.1)- GND- 將電路連接至PC的RS232後，開啟超級終端機，設定9600bps傳輸(硬體控制-無)，由鍵盤輸入字元，觀察MCU接收到的值 PC RS232 RS232 Driver MCU UART 線材：5母5公 UART04.C 按鍵盤’1’(注意電壓的不同) MSP430 Rx(P1.1)- GND- PC RS232 RS232 Driver MCU UART PC端傳來的原始訊號 轉換後傳至MCU的訊號 如前一頁，請更改程式與PC端設定，修改傳輸速度為19200bps，以示波器觀察波型變化。 UART05.C 試由超級終端機輸入1與2觀察實驗板上LED燈變化 MSP430 Rx(P1.1)- GND- PC RS232