CC2540 TIMER1

wang wx

Other Parts Discussed in Thread: CC2540

你好，我们现在用KEYFOB例程时，硬件把BUZZER的io口从1-6该到1-2了，也就是说原来的timer3需要修改成timer1，在仿照timer3配置timer1时，发现没有register去设置timer1的stop和start。有没有timer1的使用实例？或者我要怎么配置timer1来达到我设置蜂鸣器频率的要求？

12 年多前

0 wang wx 12 年多前

Intellectual 350 points

start函数里下面一段：

    // Update registers
    T1CTL &= ~0xE0;
    T1CTL |= prescaler;
    T1CC0L = (uint8)ticks;

    // Start timer
    T1CTL |= 0x10;

void buzzerStop(void)
{
#if defined ( CC2540_MINIDK )
T1CTL &= ~0x10; // Stop timer 1

#endif
}

以上红色部分配置不正确，能帮忙指出该怎么修改吗？

0 Yan 12 年多前回复 wang wx

TI__Mastermind 39565 points

Hi Wang wx,

timer 1 跟 timer 3 寄存器结构有很大不一样.

首先timer 1是16-bit的一个counter, timer 3是8-bit的.

timer 1里面并没有clear的寄存器配置, 也没有overflow interrupts的配置.

因此不推荐你使用timer 1.

你可以用timer 4, 结构配置基本跟timer 3是一样的, 你完全可以参照timer 3的配置去写代码.

0 wang wx 12 年多前回复 Yan

Intellectual 350 points

Hi Yan,

硬件已经做成这样只能用timer 1了，通过看swru191c.pdf里timer 1的寄存器，软件修改如下：

void buzzerInit(void)
{
#if defined ( CC2540_MINIDK )
    // Buzzer connected at P1_2
    // We will use Timer 1 Channel 0 at alternate location 2
    // Channel 0 will toggle on compare with 0 and counter will
    // count in up/down mode to T1CC0.

    PERCFG |= 0x40;             // Timer 1 Alternate location 2
    P1DIR |= 0x04;              // P1_2 = output
    P1SEL |= 0x04;              // Peripheral function on P1_2

    T1STAT |= 0x20;             // Disable Timer 1 overflow interrupts
    T1CTL |= 0x03;              // Timer 1 mode = 1 - Up/Down

    T1CCTL0 &= ~0x40;           // Disable channel 0 interrupts
    T1CCTL0 |= 0x04;            // Ch0 mode = compare
    T1CCTL0 |= 0x10;            // Ch0 output compare mode = toggle on compare
#endif
}

uint8 buzzerStart(uint16 frequency)
{
#if defined ( CC2540_MINIDK )
    uint8 prescaler = 0;

    // Get current Timer tick divisor setting
    uint8 tickSpdDiv = (CLKCONSTA & 0x38)>>3;
    // Check if frequency too low
    if (frequency < (244 >> tickSpdDiv)){   // 244 Hz = 32MHz / 256 (8bit counter) / 4 (up/down counter and toggle on compare) / 128 (max timer prescaler)
        buzzerStop();                       // A lower tick speed will lower this number accordingly.
        return 0;
    }

    // Calculate nr of ticks required to achieve target frequency
    uint32 ticks = (8000000/frequency) >> tickSpdDiv;      // 8000000 = 32M / 4;

    // Fit this into an 8bit counter using the timer prescaler
    while ((ticks & 0xFFFF0000) != 0)
    {
        ticks >>= 1;
        prescaler += 4;
    }
    // Start timer
    T1CTL |= 0x03;              // Timer 1 mode - Up/Down

    // Update registers
    T1CTL &= ~0x0C;
    T1CTL |= prescaler;
    T1CC0H = (uint8)(ticks>>8);
    T1CC0L = (uint8)ticks;
#endif

    return 1;
}

void buzzerStop(void)
{
#if defined ( CC2540_MINIDK )
    T1CTL &= ~0x03;             // Stop timer 1
#endif
}
发现PIO1-2上输出的波形是不联系的，单就timer 1的设置来看，这一段配置有什么问题吗？