My custom T3.2 device is unable to boot / get programmed using a virgin MK20DX256VLH. If I swap out the MK20 for a preprogramed one, then there are no issues. The device boots perfectly fine, and the program button works as expected.
Here are some observations I've made when a virgin MK20DX256VLH is installed:
1. The PROGRAM line show 3.2V and drops 11mV while the program button is pressed.
2. The RESET line is showing 3.2V and drops to about 1.5 mV while the program button is pressed.
1. The crystal isn't oscillating.
2. The current consumption is only 10 mA (probably from the active components on the board)
3. While the program button is pressed, the current goes up to 13 mA.
4. When the program button is released, the current briefly goes up to about 16 mA and then falls back down to 10 mA
Any suggestions as to what the cause of this problem might be?
Here are some observations I've made when a virgin MK20DX256VLH is installed:
1. The PROGRAM line show 3.2V and drops 11mV while the program button is pressed.
2. The RESET line is showing 3.2V and drops to about 1.5 mV while the program button is pressed.
1. The crystal isn't oscillating.
2. The current consumption is only 10 mA (probably from the active components on the board)
3. While the program button is pressed, the current goes up to 13 mA.
4. When the program button is released, the current briefly goes up to about 16 mA and then falls back down to 10 mA
Any suggestions as to what the cause of this problem might be?
Last edited: