DSP2808 83 pin (GPIO24), 3K resistance pulled-down, and power on 200ms of DSP reset time, 83 pin outputs a square wave signal shown in the pic below.
As shown in the pic below， 1.8v is a little faster than 3.3v, after power on, we will keep the DSP reset for 200ms, the influence of power on time sequence can be ignored.
During the reset period, the GPIO24 port outputs a square wave.
Our problem is:
1 the 3K resistance is pulled down, some control panel output square wave whose amplitude is 0.5v, while some control panel output square wave whose amplitude is 3V (that is a risk), what is the reason?
2 when restoring the output square wave, what is the internal state of GPIO24? Is it equivalent to a pulled up resistance and what is the value of the resistance?
CH1：reset signal CH2：3.3V CH3：1.8V CH4：GIPO24（BOOST1_PWM）
