[FAQ] AM625 / AM623 / AM625SIP / AM625-Q1 / AM620-Q1 / AM62A7 / AM62A3 / AM62P / AM62P-Q1 Custom board hardware design – EXTINTn pin pullup connection

Hi Board designers, 

Refer below inputs for the EXTINTn related queries.

EXTINTn

Although the buffer type is open drain type the TX (transmitter) and RX (receiver) are off during power-up and so this pin can be left unconnected (open) when not used.

We would only need external pull-up when the pins were being used If their receivers had been turned off by default. 

Additional information

MCU_I2C0 and WKUP_I2C0

Pls refer the MCU_I2C0 interface power-up configuration in the data sheet.

We have external pull-up requirements for the I2C pins because the receiver is turned on by default, there is no internal pull option, and the output buffer will only be driven when the subsystem is actively driving a low logic state since is an open-drain output buffer.  The external pull-up are needed to hold the input buffer (receiver) in a valid logic state. 

We have the pin connectivity requirements defined in the data sheet for the I2C interfaces. A pullup is recommended on the I2C interface irrespective of IO configuration or pin usage.

Regards,

Sreenivasa

Hi Board designers, 

Please note additional inputs on the EXTINTn IO

Open drain output type IO EXTINTn has slew rate limit specified when pulled to 3.3V supply.
Add an RC at the input.

Regards,

Sreenivasa