LTE Module SeriesEC21 Hardware DesignEC21_Hardware_Design Confidential / Released 54 / 943.18. Wireless Connectivity InterfacesEC21 supports a low-power SDIO 3.0 interface for WLAN and a UART/PCM interface for BT.The following table shows the pin definition of wireless connectivity interfaces.Table 22: Pin Definition of Wireless Connectivity InterfacesPin Name Pin No. I/O Description CommentWLAN PartSDC1_DATA3 129 IO SDIO data bus D3 1.8V power domainSDC1_DATA2 130 IO SDIO data bus D2 1.8V power domainSDC1_DATA1 131 IO SDIO data bus D1 1.8V power domainSDC1_DATA0 132 IO SDIO data bus D0 1.8V power domainSDC1_CLK 133 DO SDIO clock 1.8V power domainSDC1_CMD 134 IO SDIO command 1.8V power domainWLAN_EN 136 DO WLAN function control viaFC20 module. Active high. 1.8V power domainCoexistence and Control PartPM_ENABLE 127 DO External power control 1.8V power domainWAKE_ON_WIRELESS 135 DI Wake up the host (EC21 module)by FC20 module. 1.8V power domainCOEX_UART_RX 137 DI LTE/WLAN&BT coexistence signal 1.8V power domainCOEX_UART_TX 138 DO LTE/WLAN&BT coexistence signal 1.8V power domainWLAN_SLP_CLK 118 DO WLAN sleep clockBT Part*BT_RTS* 37 DI BT UART request to send 1.8V power domainBT_TXD* 38 DO BT UART transmit data 1.8V power domainBT_RXD* 39 DI BT UART receive data 1.8V power domainQuectelConfidential
