What is the state of IO during the period from power-on to boot on MCU LPC32?

[Guestsun]

What is the state of IO during the period from power-on to boot on MCU LPC32?

[frank_m]

In a tristate mode, effectively off.

A common feature of all ARM Cortex M devices is, all peripheral units must be explicitely enabled (clock and power) to operate.
These peripherals are by default off at reset.

Very few exceptions might apply, like dedicated quartz input pins or JTAG/SWD pins.

[xiangjun_rong]

Hi,

Pls refer to data sheet of LPC32xx, the attribute of a pin is input(I), Output(O), bidirectional(I/O) , analog, power.

For the bidirectional I/O pin and Input pin, I suppose that the state of IO during the period from power-on to boot are in input mode, except for JTAG pins.

Hope it can help you

BR

XiangJun Rong