conga-SMX8 Serial Ports
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Serial Ports on conga-SMX8
The conga-SMX8 offers support for five serial ports (plus one) for general purpose. An additional port is used for debug output from the SCU.
Three of the serial ports available on the SMARC connector (SER0, SER1, SER3) are assigned to the application cores (i.e. lpuart1, lpuart3, lpuart4).
Furthermore, SMARC SER2 is assigned to the first M4 controller.
On the onboard console connector (X4), two additional serial ports are available. One of them is assigned to the application cores (lpuart0, i.e. the console uart), the other
is connected to the SCU uart (and used as SCU debug console).
Another additional uart can be made available on the SMARC GPIO5 and GPIO10 pins. If no PWMOUT/GPIO functionality is required, these pins can be configured as uart using a special device tree setup.
default mapping
function | pins (i.MX8QM ball) | device | location | level | wire | SEVA carrier |
|---|---|---|---|---|---|---|
SCU debug output | SCU_UART0 (AV44/AU43) | SCU UART | onboard console connector X4, 2nd | RS232 | 2 wire (TXD/RXD) | |
standard console | UART0, RX/TX (AV48/AV50) | lpuart0 (0x5a060000) | onboard console connector X4, 1st | RS232 | 2 wire (TXD/RXD) | |
SMARC SER 0 | UART1 (AY48/AT44/AR43/AV46) | lpuart1 (0x5a070000) | SMARC con. X6, P129-P132 | 1.8V | 4 wire (TXD/RXD/RTS/CTS) | SEVA X18, Pin 2/3/7/8 |
SMARC SER 1 | M41_GPIO (AU47/AP44) | lpuart3 (0x5a090000) | SMARC con. X6, P134/P135 | 1.8V | 2 wire (TXD/RXD) | SEVA X17, Pin 5/3 |
SMARC SER 2 | M40_UART0 (AU51/AM44) | M40 UART | SMARC con. X6, P136/P137 | 1.8V | 2 wire (TXD/RXD) | SEVA X37, Pin 41/43 |
SMARC SER 3 | M40_GPIO, UART4 (AU53/AR47) | lpuart4 (0x5a0a0000) | SMARC con. X6, P140/P141 | 1.8V | 2 wire (TXD/RXD) | SEVA X37, Pin 9/11 |
SMARC GPIO 10/GPIO 5 (PWMOUT) | UART0, CTS/RTS (AW49/AU45) | lpuart2* (0x5a080000) | SMARC con. X6, P118/P113 | 1.8V | 2 wire (TXD/RXD) | SEVA X37, Pin 25/12 |
\* lpuart2 is shared with SMARC GPIO 5 and 10. In order to enable lpuart2, the device tree setup has to be adjusted. Please notice that the physical signals for lpuart2 and SMARC SER2 are different, so don't mix them up.
quick interface test
In order to send/receive a test string to/from a particular interface (e.g. lpuart1, w/o flowcontrol):
export serdev=/dev/ttyLP1
stty -F ${serdev} 115200
stty -F ${serdev} raw ispeed 115200 ospeed 115200 cs8 -crtscts
echo "The quick brown Fox ..." > ${serdev}
cat ${serdev}