STM8L151Gx ADC1转换值检索时间长

我有一个问题源于纯粹的好奇心，因为我还在学习STM8 MCU结构。在ADC的一般设置，单模转换和软件触发时，一旦ADC完成采样和转换周期，我们必须调用ADC_GetConversionValue（ADC1）。此函数应从寄存器中检索要在本地保存的值。我希望这个功能不会花费太长时间，但是通过粗略测量时间（在函数周围切换GPIO引脚并在示波器上查看）来执行函数，我测量5us。当您尝试测量短脉冲波形但需要高数据点采集时，这变得非常重要。有没有人解释为什么这个检索需要那么长时间？



以下为原文




I have a question rooted in pure curiosity as I am still learning my around the STM8 MCU structure. In the general setup of the ADC, single mode conversion and software triggered,  we have to call ADC_GetConversionValue(ADC1) once the ADC has finished its sampling and conversion cycles. This function should retrieve a value from the register to be saved locally. I expected this function to not take too long, but by roughly measuring the time(toggling GPIO pins around the functions and viewing on an oscilloscope) for the function to execute, I measure 5us. This becomes pretty substantial when you are trying to measure short pulse waveforms, but need a high data point collection set. Does anyone have the explanation as to why this retrieval takes that long?