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TMS320F28034-Q1: DSP芯片上电瞬间GPIO口的电平状态问题

Part Number: TMS320F28034-Q1

从28034上电瞬间到执行Main函数程序前这段时间内(大概有30ms),发现一个配置为GPIO口的引脚会输出一个电平,大概是0.7V。Main函数开始执行的时候,该GPIO可以正常控制高低电平。

请问这样算是正常的么?

  • 不知道你提到的GPIO具体是哪一个GPIO,芯片datasheet中有对芯片的GPIO初始化上下拉有说明的:

    All GPIO pins are I/O/Z and have an internal pullup, which can be selectively enabled/disabled on a per-pin basis. This feature only applies to the GPIO pins. The pullups on the PWM pins are not enabled at reset. The pullups on other GPIO pins are enabled upon reset. The AIO pins do not have an internal pullup.

  • 测试的引脚是GPIO18。是不是非PWM复选和AIO的引脚GPIO默认都有上拉?这样的结果是上电瞬间这类型的GPIO会有一个30多ms时间的高电平?

  • 是的,默认都有上拉,不过高电平的时间跟上电时间有关,不是确定的。