u-blox SARA-R4 Series System Integration Manual

Contents

SARA-R4 series - System Integration ManualUBX-16029218 - R06 System descriptionPage 27 of 1021.9.4 SDIO interfaceThe SDIO interface is not supported by “00”, “01” and “02” product versions: the SDIO interface pinsshould not be driven by any external device.SARA-R4 series modules include a 4-bit Secure Digital Input Output interface (SDIO_D0, SDIO_D1, SDIO_D2,SDIO_D3, SDIO_CLK, SDIO_CMD) designed to communicate with external compatible SDIO devices.1.9.5 DDC (I2C) interfaceThe I2C interface is not supported by “00” and “01” product versions: the I2C interface pins should not bedriven by any external device.SARA-R4 series modules include an I2C-bus compatible DDC interface (SDA, SCL) available to communicate witha u-blox GNSS receiver and with external I2C devices as an audio codec: the SARA-R4 module acts as an I2Cmaster which can communicate with I2C slaves in accordance with the I2C bus specifications [9].The SDA and SCL pins have internal pull-up to V_INT, so there is no need of additional components on theexternal application board.1.10 AudioAudio is not supported by “00”, “01” and “02” product versions: the I2S interface pins should not bedriven by any external device.SARA-R4 series modules support VoLTE (Voice over LTE Cat M1 radio bearer) for providing audio services.SARA-R4 series modules include an I2S digital audio interface to transfer digital audio data to/from an externalcompatible audio device.The digital audio interface can be made available as alternative function, in mutually exclusive way, over the SPIinterface pins (I2S_WA / SPI_MOSI, I2S_RXD / SPI_MISO, I2S_CLK / SPI_CLK, I2S_TXD / SPI_CS).