# QUP and GPIO configurations Source: [https://docs.qualcomm.com/doc/80-88500-3/topic/4_Configure_QUP_and_GPIO_settings.html](https://docs.qualcomm.com/doc/80-88500-3/topic/4_Configure_QUP_and_GPIO_settings.html) The Qualcomm universal peripheral (QUP) v3 serial engine is a hardware core that supports multiple low-speed peripheral devices such as universal asynchronous receiver/transmitter (UART), serial peripheral interface (SPI), and interintegrated circuit (I^2^C). These peripherals are used to connect to the sensors, Bluetooth® wireless technology, and touchscreen-based devices. The QUP v3 serial engine supports access from multiple hardware entities in the system. Each entity has its own execution environment, a separate address space, and an interrupt line. All serial engines are not available for customization. A few serial engines are used by the reference software to work with the RB5 development kit. Retain the same assignment and use only the unused GPIOs for any custom peripheral interface. For custom-board designs, there is flexibility to modify the serial engines (SE). Note: Linux Embedded systems do not support reading GPIO configurations. Support to read GPIO values using devmem will be enabled in the future version. - **[About QUP ports](https://docs.qualcomm.com/doc/80-88500-3/topic/5_About_QUP_ports.html)** - **[GPIO configurations](https://docs.qualcomm.com/doc/80-88500-3/topic/6_Configure_GPIO_direction_and_value.html)** Last Published: Sep 26, 2023 [Previous Topic Introduction](https://docs.qualcomm.com/bundle/publicresource/80-88500-3/topics/1_Introduction.md) [Next Topic About QUP ports](https://docs.qualcomm.com/bundle/publicresource/80-88500-3/topics/5_About_QUP_ports.md)