2.5.14. GPIO Pins During Power Sequencing
Adhere to the these guidelines to prevent unnecessary current draw on the I/O pins located in the GPIO banks. These guidelines apply for unpowered, power up to power-on reset (POR), POR delay, POR delay to configuration, configuration, initialization, user mode, and power down device states.
- The I/O pins in the GPIO banks can be tri-stated, driven to ground, or driven to the VCCIO_PIO level.
- While the device is powering up or down:
- The input signals of an I/O pin, at all times, must not exceed the I/O buffer power supply rail of the bank where the I/O pin resides.
- If you use a pin in a GPIO bank with 1.5 V VCCIO_PIO, the pin voltage must not exceed the VCCIO_PIO rail or 1.2 V, whichever is lower.
- While the device is powering up, powering down, or not turned on, the GPIO pins can tolerate a maximum of 10 mA per pin and a total of 100 mA per GPIO bank.
- After the device fully powers up, the voltage levels for the GPIO pins must not exceed the DC input voltage (VI) value.
|The VCCIO_PIO pin ramps up and at period X, the VCCIO_PIO voltage is 1.1 V.
|At period X, keep the signals driven by the device connected to the GPIO I/O pin at a voltage of 1.1 V or lower.
|The 1.5 V VCCIO_PIO pin ramps up and the voltage continues to rise pass the 1.2 V level.
|Keep the GPIO pin voltage at 1.2 V or lower until the device fully powers up.