The pins are in high-z after reset until the configuration is done. So when using an external pull up resistor (5K) will keep the pin high.
I have implemented similar functionality using other microcontrollers and they do keep their pin state after a software reset, so I thought it was also possible with psoc without using an external resistor.
Please let me ask a question.
I understand that a power supply control pin is driven by the PRoC BLE which becomes Hi-Z during the PRoC BLE's reset sequence.
Then, how do this power supply control signal play during power-on? Who does enable the power supply?
If this control signal is re-defined as a LOW-ACTIVE signal pulled up to VDD to disable the power supply, it is better to understand the system.
The power supply enable is controlled by 2 inputs the signal from the proc and a button, that is connected to a battery.
Initially, to turn on the system, the button is pressed this enables the power supply and the first action the proc module does is set its signal high to keep the power supply enabled. Once the user releases the button the power supply remains on because of the signal from the module.
The button is also connected to an input of the proc module, for user actions. For example to turn off the module the button is pressed for a certain amount of time and the proc module sets the signal low. After the user releases the button the power supply is turned off.
To enter the bootloader, I write a value to a ble characteristic and the program sets that it wants to enter the bootloader and does the software reset. The problem I have, as mentioned before, is that the signal switches to the high impedance state, and it's not possible to connect a pullup resistor with the current pcb design.
What I would like to know is if there is a way to jump to the bootloader so that the output remains high.
The Bootloader component has the Bootloader_Start() function under its datasheet. I would start there. (It does mention that it resets the unit upon successful loading of a new bootload image however).