LPC1768定时器编程示例分析

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资源摘要信息:"LPC1769定时器编程示例" LPC1769是NXP公司生产的一款基于ARM Cortex-M3的微控制器(MCU),广泛应用于需要高性能和高集成度的嵌入式系统中。定时器是微控制器中一个非常重要的外设,可以用于测量时间间隔、产生时间延迟、计数事件等。 1. LPC1769定时器概述 LPC1769拥有多个定时器,这些定时器可以工作在不同的模式下。其中包括: - 定时器模式:可以用于产生精确的时间延迟。 - 计数器模式:用于记录事件的数目。 - PWM(脉冲宽度调制)模式:用于控制电机速度,调节LED亮度等。 - 输入捕获模式:用于测量输入信号的频率和脉冲宽度。 2. 定时器编程基础 定时器编程通常涉及到以下几个关键步骤: - 定时器初始化:配置定时器的工作模式,设定时间基准,设置计数器的起始值和终止值。 - 定时器中断配置:根据需要配置定时器中断,如定时器溢出中断,输入捕获中断等。 - 定时器启动:启动定时器,使能中断,开始定时器功能。 3. LPC1769定时器的具体应用 在LPC1769中,定时器的应用非常广泛。例如,使用定时器来实现一个简单的秒表功能,可以使用定时器的定时中断功能,每隔一定时间产生一次中断,并在中断服务程序中更新显示的时间。 4. LPC1769定时器编程实例 在给定的文件标题“int_timer - Copy_lpc1769_”中,我们可以推断这可能是一个关于LPC1769定时器中断服务程序的示例代码。通常情况下,中断服务程序需要完成以下几个任务: - 清除中断标志:中断发生后,必须清除中断标志,以允许定时器继续产生中断。 - 更新变量或状态:根据定时器中断发生的情况,更新内部变量或状态。 - 重新配置定时器:如果需要,可以在这个时候修改定时器的相关配置。 在具体的编程实践中,开发者需要参考NXP提供的LPC1769的参考手册(Reference Manual)以及数据手册(Datasheet),这两份文档详细描述了定时器的每个寄存器的功能和配置方法,以及如何使用这些寄存器来完成上述的编程步骤。 5. 结语 掌握LPC1769定时器的编程对于深入开发基于此MCU的应用至关重要。定时器的正确配置和使用能够极大提升应用的性能和效率。开发者应当熟悉定时器的各种工作模式,并能够在实际项目中灵活运用这些模式来满足应用需求。此外,理解中断管理机制也是确保程序稳定运行的基础。在编程时,合理规划中断优先级和处理方式可以有效避免系统的不可预测行为。

重写下面代码;timer_handle_t itcs_timer_init(timer_handle_t handle, timer_event_cb_t cb_event) { timer_priv_t *timer_priv = handle; if (timer_priv->idx < 0 || timer_priv->idx >= CONFIG_TIMER_NUM) { return NULL; } set_clock_type("cpu-pclk"); // printf("enter timer init fun in driver\n"); uint32_t tempreg = 0; switch (timer_priv->idx) { case 0: timer_priv->base = ITCS_TIMER0_BASE; break; case 1: timer_priv->base = ITCS_TIMER1_BASE; break; default: break; } // printf("unit %d ,timeridx %d, base addr // %08x\n",timer_priv->idx,timer_priv->timeridx,timer_priv->base); switch (timer_priv->timeridx) { case 1: tempreg = readl(timer_priv->base + TIMER_CCR_CONTROL_C1); tempreg |= CCR_RST_ENABLE; writel(tempreg, timer_priv->base + TIMER_CCR_CONTROL_C1); tempreg = readl(timer_priv->base + TIMER_IER_C1); tempreg &= ~(IER_EVNT_ENABLE | IER_ITRV_ENABLE | IER_M1_ENABLE | IER_M2_ENABLE | IER_M3_ENABLE); writel(tempreg, timer_priv->base + TIMER_IER_C1); if (timer_priv->idx == 0) { timer_priv->irq = TTC0_TIMER1_IRQn; request_irq(TTC0_TIMER1_IRQn, itcs_timer_irq, "itcs_timer_irq01", timer_priv); } else { timer_priv->irq = TTC1_TIMER1_IRQn; request_irq(TTC1_TIMER1_IRQn, itcs_timer_irq, "itcs_timer_irq11", timer_priv); } break; case 2: tempreg = readl(timer_priv->base + TIMER_CCR_CONTROL_C2); tempreg |= CCR_RST_ENABLE; writel(tempreg, timer_priv->base + TIMER_CCR_CONTROL_C2); tempreg = readl(timer_priv->base + TIMER_IER_C2); tempreg &= ~(IER_EVNT_ENABLE | IER_ITRV_ENABLE | IER_M1_ENABLE | IER_M2_ENABLE | IER_M3_ENABLE); writel(tempreg, timer_priv->base + TIMER_IER_C2); if (timer_priv->idx == 0) { timer_priv->irq = TTC0_TIMER2_IRQn; request_irq(TTC0_TIMER2_IRQn, itcs_timer_irq, "itcs_timer_irq02", timer_priv); } else { timer_priv->irq = TTC1_TIMER2_IRQn; request_irq(TTC1_TIMER2_IRQn, itcs_timer_irq, "itcs_timer_irq12", timer_priv); } break; case 3: tempreg = readl(timer_priv->base + TIMER_CCR_CONTROL_C3); tempreg |= CCR_RST_ENABLE; writel(tempreg, timer_priv->base + TIMER_CCR_CONTROL_C3); tempreg = readl(timer_priv->base + TIMER_IER_C3); tempreg &= ~(IER_EVNT_ENABLE | IER_ITRV_ENABLE | IER_M1_ENABLE | IER_M2_ENABLE | IER_M3_ENABLE); writel(tempreg, timer_priv->base + TIMER_IER_C3); if (timer_priv->idx == 0) { timer_priv->irq = TTC0_TIMER3_IRQn; request_irq(TTC0_TIMER3_IRQn, itcs_timer_irq, "itcs_timer_irq03", timer_priv); // printf("unit timer1 ret=%08x , request irq3 success!\n",ret); } else { timer_priv->irq = TTC1_TIMER3_IRQn; request_irq(TTC1_TIMER3_IRQn, itcs_timer_irq, "itcs_timer_irq13", timer_priv); // printf("unit timer1 ret=%08x , request irq3 success!\n",ret); } break; default: return NULL; } timer_priv->cb_event = cb_event; // printf("init status irq id num:%d\n",timer_priv->irq); // printf("INIT TIMER %d Timer Count No %d SUCCESS\n", timer_priv->idx, // timer_priv->timeridx); return (timer_handle_t)timer_priv; }

2023-02-17 上传
2023-02-18 上传

int itcs_timer_irq(int idx, void *arg) { timer_priv_t *timer_priv = (timer_priv_t *)arg; uint32_t tempregisr = 0; switch (timer_priv->timeridx) { case 1: tempregisr = readl(timer_priv->base + TIMER_ISR_C1); // printf("BEFORE READ COUNT1 ISR STAT RET :%08x\n",tempregisr); if (GET_BIT(tempregisr, 4) == 1) { // printf("OVERFLOW INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_OVERFLOW_INTERRUPT; } if (GET_BIT(tempregisr, 0) == 1) { g_endtime = get_timer(0); // printf("INTERVAL INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_INTERVAL_INTERRUPT; } if (GET_BIT(tempregisr, 1) == 1) { g_endtimematch1 = get_timer(0); // printf("MATCH1 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH1_INTERRUPT; } if (GET_BIT(tempregisr, 2) == 1) { g_endtimematch2 = get_timer(0); // printf("MATCH2 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH2_INTERRUPT; } if (GET_BIT(tempregisr, 3) == 1) { g_endtimematch3 = get_timer(0); // printf("MATCH3 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH3_INTERRUPT; } tempregisr = readl(timer_priv->base + TIMER_ISR_C1); // printf("AFTER READ COUNT1 ISR STAT RET :%08x\n",tempregisr); break; case 2: tempregisr = readl(timer_priv->base + TIMER_ISR_C2); // printf("BEFORE READ COUNT2 ISR STAT RET :%08x\n",tempregisr); if (GET_BIT(tempregisr, 4) == 1) { // printf("OVERFLOW INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_OVERFLOW_INTERRUPT; } if (GET_BIT(tempregisr, 0) == 1) { g_endtime = get_timer(0); // printf("INTERVAL INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_INTERVAL_INTERRUPT; } if (GET_BIT(tempregisr, 1) == 1) { // printf("MATCH1 INTERRUPT OCCUR\n"); g_endtimematch1 = get_timer(0); timer_priv->enum_interrupt = TIMER_MATCH1_INTERRUPT; } if (GET_BIT(tempregisr, 2) == 1) { g_endtimematch2 = get_timer(0); // printf("MATCH2 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH2_INTERRUPT; } if (GET_BIT(tempregisr, 3) == 1) { g_endtimematch3 = get_timer(0); // printf("MATCH3 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH3_INTERRUPT; } tempregisr = readl(timer_priv->base + TIMER_ISR_C2); // printf("AFTER READ COUNT2 ISR STAT RET :%08x\n",tempregisr); break; case 3: tempregisr = readl(timer_priv->base + TIMER_ISR_C3); // printf("BEFORE READ COUNT3 ISR STAT RET :%08x\n",tempregisr); if (GET_BIT(tempregisr, 4) == 1) { // printf("OVERFLOW INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_OVERFLOW_INTERRUPT; } if (GET_BIT(tempregisr, 0) == 1) { g_endtime = get_timer(0); // printf("INTERVAL INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_INTERVAL_INTERRUPT; } if (GET_BIT(tempregisr, 1) == 1) { g_endtimematch1 = get_timer(0); // printf("MATCH1 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH1_INTERRUPT; } if (GET_BIT(tempregisr, 2) == 1) { g_endtimematch2 = get_timer(0); // printf("MATCH2 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH2_INTERRUPT; } if (GET_BIT(tempregisr, 3) == 1) { g_endtimematch3 = get_timer(0); // printf("MATCH3 INTERRUPT OCCUR\n"); timer_priv->enum_interrupt = TIMER_MATCH3_INTERRUPT; } tempregisr = readl(timer_priv->base + TIMER_ISR_C3); // printf("AFTER READED COUNT3 ISR STAT RET :%08x\n",readregisr); break; default: break; } if (timer_priv->cb_event) { timer_priv->cb_event(timer_priv); } return 0; }

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