UMTS/HSPA Module SeriesUC20 Hardware DesignUC20_Hardware_Design Confidential / Released 26 / 843.5.1.1. UART ApplicationIf application processor communicates with module via UART interface, the following preconditions canlet the module enter into the sleep mode. Execute AT command AT+QSCLK=1 to enable the sleep mode. Drive DTR to high level.The following figure shows the connection between the module and application processor.RXDTXDRIDTRAP_READYTXDRXDEINTGPIOGPIOModule ProcessorGND GNDFigure 3: UART Sleep ApplicationThe RI of module is used to wake up the processor, and AP_READY will detect the sleep state ofprocessor (can be configured to high level or low level detection). You should pay attention to the levelmatch shown in dotted line between module and processor.Drive DTR to low level will wake up the module.3.5.1.2. USB Application with Suspend FunctionIf application processor communicates with module via USB interface, and processor supports USBsuspend function, the following preconditions can let the module enter into the sleep mode. Execute AT command AT+QSCLK=1 to enable the sleep mode. The processor’s USB bus which is connected with the module USB interface enters into suspendedstate.The following figure shows the connection between the module and processor.
