Hello,
I'm designing a system with K64 MCU
My question regarding all GPIO's state on power-up :
1. The GPIO's state on boot is output or input ? if so, is it PU/PD/HiZ ?
2. What doe's it mean that the default function of a GPIOs is "DISABLED" ?
Looking at the reference manual - http://cache.freescale.com/files/microcontrollers/doc/ref_manual/K64P144M120SF5RM.pdf
Page 244, chapter 10.2.2 Port control and interrupt summary
"Pull enable at reset - Disabled" - so i can understand from that that the GPIO is defined as Input Hi-Z ?
Please clarify this issue for me
Thanks & Regards
Hello Eduard Razumovsky:
Mark's response is completely correct. You should look at the Default column in the pinout table.
DISABLED indicates no function after reset, so that is High-Impedance.
Pins with an analog MUX option will be connected by default after reset to their corresponding analog module.
Regards!
Jorge Gonzalez
Okay, but what about this case on my MK02Z?
powering up issue on MKE02Z GPIO
On power-up PTB4 seems to follow the VCC ramp and after PE initialization this is set as a digital output with zero value.
regards,
gaston
Hi
No pins are GPIOs outputs after reset.
If their pull-up is disabled at reset it means that there is no pull-up or pull-down connected. [Only the pins that default to JTAg use have pull-ups or downs eabled out of reset].
Some pins default to peripheral functions (see 10.3.1) and not GPIO.
If disabled out of reset, it means that there is no connected default function - the pin is not GPIO input without first setting the GPIO Mux function (Alt 1).
Regards
Mark
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