ADLINK LEC-iMX6 User Manual
Page 18
14
Interfaces
3.12 Serial (UART)
The LEC-iMX6 provides four serial interfaces: Two ports are high-speed, 4-wire ports (with TX/
RX and RTS#/CTS#), and two ports are 2-wire (with TX/RX only.) Refer to the following table.
The voltage levels of the UART interfaces are 1.8V.
3.13 SPDIF
The Sony/Philips Digital Interconnect Format (SPDIF) audio block is a stereo transceiver that
allows the processor to receive and transmit digital audio. Since the SPDIF internal data width is
24-bit, the eight most-significant bits of all registers return zeros. The SPDIF uses 2 wires, one
data output, and one input.
The voltage level of the SPDIF interface is 1.8V
3.14 I2S
The LEC-iMX6 provides one I2S audio interface, and the signals are brought out through the
I2S0 pins on the SMARC connector. The signals are shared with the SPI0 interface on the
SMARC connector. The signal that allows switching between SPI and I2S is GPIO1_IO3. The
default state is SPI (GPIO1_IO3 = low). When GPIO1_IO3 = high, I2S is switched through the
SMARC connector.
The voltage level of the I2S interface is 1.8V
3.15 CAN
The LEC-iMX6 provides two CAN (FLEXCAN) interfaces
that comply with the CAN 2.0B proto-
col specification. Two CAN bus transceivers reside on the CPU and are not required on the
module. Refer to the following table for signal designators.
The voltage level of the CAN interface is 1.8V
3.16 SD/SDIO Interface
Four parallel data lines comprise the SD/SDIO interface, supporting SD Card sockets. The
LEC-iMX6 provides a 4-bit transfer mode at the SMARC connector using the SDIO pins and the
SD2 interface of the i.MX 6 CPU. The following modes can be selected for data transfer:
SD/SDIO full speed mode (up to 25 MHz)
SD/SDIO high speed mode (up to 50 MHz)
SD/SDIO UHS-I mode (up to 208 MHz in SDR mode, up to 50 Mhz in DDR mode)
The SDIO interface can be selected as the Boot Device. The voltage level of the SD/SDIO inter-
face is 3.3V
i.MX6
SMARC connector
Bus width
UART1
SER0
4 wire bus
UART2
SER1
2 wire bus
UART5
SER2
4 wire bus
UART4
SER3
2 wire bus
i.MX6
SMARC connector
FLEXCAN1
CAN0
FLEXCAN2
CAN1