嵌入式技術(shù)及應(yīng)用實(shí)驗(yàn)定時(shí)器實(shí)驗(yàn).doc

年級(jí) 11級(jí)班級(jí)學(xué)號(hào) 11064029專業(yè) 自動(dòng)化姓名 楊勝提題目名稱實(shí)驗(yàn)三、定時(shí)器實(shí)驗(yàn)實(shí)驗(yàn)設(shè)計(jì)思路(1) 硬件電路設(shè)計(jì)TIM2定時(shí)器的通道1到4分別對(duì)應(yīng)PA.00、PA.01、PA.02和PA.03引腳，這些處理器引腳已經(jīng)以插針形式引出。(2) 軟件程序設(shè)計(jì) 根據(jù)設(shè)計(jì)任務(wù)要求，程序內(nèi)容比較簡(jiǎn)單。程序內(nèi)容主要包括：1)配置TIM2各通道均為輸出比較模式（預(yù)分頻系數(shù)設(shè)為2），設(shè)置各通道的參數(shù)（TIM2 CC1=0x8000、TIM2 CC2=0x4000、TIM2 CC3=0x2000、TIM2 CC4=0x1000）；2)在相應(yīng)的TIM2定時(shí)器中斷服務(wù)處理程序中根據(jù)定時(shí)器的值翻轉(zhuǎn)輸出電平，以輸出方波。實(shí)驗(yàn)設(shè)計(jì)要求對(duì)TIM2定時(shí)器進(jìn)行控制，使得TIM2通道1產(chǎn)生頻率為183.1Hz的方波，通道2產(chǎn)生頻率為366.2Hz的方波，通道3產(chǎn)生頻率為732.4Hz的方波，通道4產(chǎn)生頻率為1464.8Hz的方波。實(shí)驗(yàn)步驟與結(jié)果分析(1)使用Keil uVision3 通過ULINK 2仿真器連接EduKit-M3實(shí)驗(yàn)平臺(tái)，打開實(shí)驗(yàn)例程目錄TIMx_test 子目錄下的TIMx.Uv2例程，編譯鏈接工程； (2)點(diǎn)擊MDK 的Debug菜單，選擇軟件仿真模式，點(diǎn)擊Start/Stop Debug Session，將 PORTA.0、PORTA.1、PORTA.2和PORTA.3加入到邏輯分析儀中，點(diǎn)擊Run按鈕運(yùn)行程序，在邏 輯分析儀中可以看到各通道波形。 (3)如果有示波器，也可以進(jìn)行硬件調(diào)試，將EduKit-M3實(shí)驗(yàn)平臺(tái)上的PA.00、PA.01、PA.02和PA.03 引腳接入示波器。選擇項(xiàng)或Ctrl+F5鍵，遠(yuǎn)程連接EduKit-M3實(shí)驗(yàn)平臺(tái)并下載調(diào)試代碼到目標(biāo)系統(tǒng)的RAM中， 點(diǎn)擊Run按鈕或按F5開始運(yùn)行例程，在示波器上可以看到各通道的波形。 原程序仿真波形圖 修改后程序仿真波形圖示波器顯示的183.1Hz的方波和366.2Hz的方波示波器顯示的732.4Hz的方波的方波和1464.8Hz的方波主要程序代碼分析 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;TIM_OCInitTypeDef TIM_OCInitStructure;vu16 CCR1_Val = 0x8000; /設(shè)置為2929.6 Hz vu16 CCR2_Val = 0x4000; vu16 CCR3_Val = 0x2000; vu16 CCR4_Val = 0x1000; ErrorStatus HSEStartUpStatus; TIM_TimeBaseStructure.TIM_Period = 0xFFFF; /設(shè)置周期為72MHz TIM_TimeBaseStructure.TIM_Prescaler = 0x02; / 預(yù)定分頻為36 MHz TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; TIM_TimeBaseStructure.TIM_CounterMode 有如下幾種選擇。 TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = 2047;/取值在0x00000xFFFF之間 TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; TIM_OC1Init(TIM2, &TIM_OCInitStructure); TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = 1023; TIM_OC2Init(TIM2, &TIM_OCInitStructure); TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = 511; TIM_OC3Init(TIM2, &TIM_OCInitStructure); TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_Pulse = 255; TIM_OC4Init(TIM2, &TIM_OCInitStructure); /* Enable the TIM2 global Interrupt */ 使能定時(shí)器2全局中斷 NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET) TIM_ClearITPendingBit(TIM2, TIM_IT_CC1 );capture1 = TIM_GetCapture1(TIM2);TIM_SetCompare1(TIM2, capture1 + CCR1_Val ); /* TIM2_CH2 toggling with frequency = 366.2 Hz */ if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET) TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);capture2 = TIM_GetCapture2(TIM2); TIM_SetCompare2(TIM2, capture2 + CCR2_Val); /* TIM2_CH3 toggling with frequency = 732.4 Hz */ if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET) TIM_ClearITPendingBit(TIM2, TIM_IT_CC3);capture3 = TIM_GetCapture3(TIM2); TIM_SetCompare3(TIM2, capture3 + CCR3_Val); /* TIM2_CH4 toggling with frequency = 1464.8 Hz */ if (TIM_GetITStatus(TIM2, TI