大家好,我写了基于CC2541的
timer1的PWM波形输出代码,测试的时候用示波器发现了P0_3和P0_5输出波形有奇怪现象。我的相关代码在页尾贴出,附件里面也有方便大家下载,真诚希望大家可以下载,测试一下,帮助小弟一起讨论,揭开这个面纱!timer1 的channel 1 和 channel 3 是配置成PWM输出,timer1的工作模式是modulo 模式。 我设计的周期是25HZ现象一: 当CC1 = 5000和CC3 = 5000, P0_3(channel 1) 和P0_5(channel 3) 都是20ms高电平,是正常的 当CC1 = 8000和CC3 = 5000,P0_5(channel 3)是20ms的高电平PWM,是正常的。但是P0_3(channel 1)很奇怪,刚开始输出正常的PWM波形(时间大约100s多一点),然后输出持续高电平(时间大约100s多一点),然后输出是正常PWM的波形(时间大约100s多一点),就这样周而复始…… 当CC1 = 5000和CC3 = 2500,P0_3(channel 1)是20ms的高电平PWM,是正常的。但是P0_5(channel 3)同样的现象,刚开始输出正常的PWM波形(时间大约100s多一点),然后输出持续低电平(时间大约100s多一点),然后输出是正常PWM的波形(时间大约100s多一点),周而复始现象二: 当CC1 = 0和CC3 = 0, P0_3和P0_5 会输出一个脉冲(大约10ms),周期大约300s多一点。我真心的希望大家可以帮助我,测试一下,讨论! 在此先说声谢谢了!void timer1_init(void)[ uint16 pertiod = 0; halIntState_t intState; HAL_ENTER_CRITICAL_SECTION(intState); //close interrupt /*IO configuration, use in compare output channel 1 -> P0_3, channel 3 -> P0_5 */ P0SEL |= (BV(3)|BV(5)); P0DIR |= (BV(3)|BV(5)); /*USART0 / USART1 IO location -> Alternative 2 location*/ PERCFG |= 0x03; /*Set the prescaler divider value DIV[1:0]=11 f= 32MHZ / 128=0.25MHZ */ T1CTL |= 0x0C; /*timer1 channel 0 register configuration*/ T1CCTL0 |= 0x04; //select compare mode T1CCTL0 |= 0x40; //enable interrupt request /*timer1 channel 1 register configuration, */ T1CCTL1 |= 0x04; //select compare mode T1CCTL1 |= 0x30; //CMP[2:0]=110, set when equal T1CC0,clear when equal T1CC1 T1CCTL1 &= ~0x40; //disable interrupt request /*timer1 channel 3 register configuration, */ T1CCTL3 |= 0x04; //select compare mode T1CCTL3 |= 0x30; //CMP[2:0]=110, set when equal T1CC0,clear when equal T1CC3 T1CCTL3 &= ~0x40; //disable interrupt request /*enable T1 interrupt*/ IEN1 |= 0x02; /*close timer1 overflow interrupt*/ TIMIF &= ~0x40; /*close timer1 channel 2&4 interrupt*/ T1CCTL2 &= ~0x40; T1CCTL4 &= ~0x40; /*set timer1 period T1CC0 //0x2710 = 10000; T=10000*4(us); f = 25HZ */ period = 0x2710; T1CC0H = (uint8)((period&0xFF00)>>8); T1CC0L = (uint8)((period&0x00FF)); /*clear timer1 counter*/ T1CNT = 0x00; /*set timer1 mode,and start timer1*/ T1CTL |= 0x02; HAL_EXIT_CRITICAL_SECTION(intState); //open interrupt ]//===============================================================================void change_pwm_value(uint8 channel, uint16 value)[ switch(channel) [ case 1: [ T1CC1H = (uint8)((value&0xFF00)>>8); T1CC1L = (uint8)((value&0x00FF)); ] break; case 3: [ T1CC3H = (uint8)((value&0xFF00)>>8); T1CC3L = (uint8)((value&0x00FF)); ] break; default: break; ]]//======================================================================================static void simpleBLEPeripheral_HandleKeys( uint8 shift, uint8 keys )[ VOID shift; // Intentionally unreferenced parameter if( keys & HAL_KEY_SW_1) [ change_pwm_value(1, 5000); change_pwm_value(3, 5000); ] if( keys & HAL_KEY_SW_2) [ change_pwm_value(1, 8000); change_pwm_value(3, 5000); ] if( keys & HAL_KEY_SW_3) [ change_pwm_value(1, 5000); change_pwm_value(3, 2500); ]]