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BBxm 看门狗定时器

Zhiwen He
Prodigy 180 points


板子加电后子隔一段时间就会reset，发现watchdog 2是默认开启的， 定时reset，所以想关闭定时器

手册里写到：

程序运行之后定时器并没有停止工作，最终发现需要在写入寄存器之后加入空循环，让系统等待一段时间，停止定时器的命令才会生效

*reg_wdtimer2_wspr = 0x0000AAAA;
while (*reg_wdtimer2_wspr & ~0x0000AAAA){};
for (i=0; i<100; i++){};    // 空循环
*reg_wdtimer2_wspr = 0x00005555;
while (*reg_wdtimer2_wspr & ~0x00005555){};
for (i=0; i<100; i++){};

但手册里并没有提到这一点， 也不知道到底应该等多久

有没有什么更好的办法关闭定时器？

我也试着关闭iclk和fclk， 但似乎不起作用

  • 0
    Prodigy 180 points

    还有个问题是看门狗关闭之后修改参数再重新开启，代码如下，用过用xds100v2逐行调试的时候没有问题，但存到sd卡在板子上就运行不了， uart也不输出， 如果只保留关闭看门狗的代码， 注释掉修改参数和开启看门狗的代码， 程序在板子上就能正常运行， 请问这又是为什么？

    // disable watchdog 2
    uart_write("Turn off watchdog 2...");
    *reg_wdtimer2_wspr = 0x0000AAAA;
    for (i=0; i<100; i++){}; // It takes sometime to make the change on register.
    while (*reg_wdtimer2_wspr & ~0x0000AAAA){};
    for (i=0; i<100; i++){};
    *reg_wdtimer2_wspr = 0x00005555;
    while (*reg_wdtimer2_wspr & ~0x00005555){};
    /*
    *reg_wdtimer2_wldr = 0x0;
    // *reg_wdtimer2_wtgr = 0xFFFFF000;

    // enable watchdog 2
    uart_write("Turn on watchdog 2...");
    *reg_wdtimer2_wspr = 0x0000BBBB;
    for (i=0; i<100; i++){}; // It takes sometime to make the change on register.
    while (*reg_wdtimer2_wspr & ~0x0000BBBB){};
    *reg_wdtimer2_wspr = 0x00004444;
    for (i=0; i<100; i++){};
    while (*reg_wdtimer2_wspr & ~0x00004444){};

  • 0 回复 Zhiwen He
    TI__Guru 64206 points

    while检查搞错寄存器了，是要检查WDT_WWPS[W_PEND_WSPR]，直到为0（no pending)再往下走。

    20.4.3.8 Start/Stop Sequence for Watchdog Timers (Using the WDT_WSPR Register)
    To start and stop a watchdog timer, access must be made through the start/stop register (WDT_WSPR)
    using a specific sequence.
    To disable the timer, follow this sequence:
    1. Write XXXX AAAAh in WDT_WSPR.
    2. Poll for posted write to complete using WDT_WWPS.W_PEND_WSPR.
    3. Write XXXX 5555h in WDT_WSPR.
    4. Poll for posted write to complete using WDT_WWPS.W_PEND_WSPR.


    To enable the timer, follow this sequence:
    1. Write XXXX BBBBh in WDT_WSPR.
    2. Poll for posted write to complete using WDT_WWPS.W_PEND_WSPR.
    3. Write XXXX 4444h in WDT_WSPR.
    4. Poll for posted write to complete using WDT_WWPS.W_PEND_WSPR.
    All other write sequences on the WDT_WSPR register have no effect on the start/stop feature of the
    module.