21 asynchronous serial ports, Asynchronous serial ports – Kontron SMARC-sAT30 User Manual
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User’s Guide
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3.2.21 Asynchronous Serial Ports
The SMARC sAT30 module supports four UARTs (SER0:3). UARTs SER0 and SER2 supports flow control signals (RTS,
CTS). UARTs SER1 and SER3 do not support flow control. When working with Linux for Tegra (L4T), SER 1 is used for T30
CPU debugging.
The sAT30 asynchronous serial port signals have a 1.8V level signal swing. They can be converted to RS232 level and
polarity signals by using a suitable RS232 transceiver. There are transceivers available that accept a 1.8V signal level:
some examples include the Texas Instruments TRS3253E, the Maxim MAX3218 and the Linear Technology LTC2801.
Note that RS232 transceivers invert the signal; a logic ‘1’ is a negative voltage (-3.0V to -15V) and a logic ‘0’ a positive
voltage (3.0V to 15V) on the RS232 line. Asynchronous serial ports interface signals are exposed on the SMARC
sAT30 edge connector as shown below:
SMARC sAT30 Edge finger
NVIDIA T30 CPU
Net Name
Notes
Pin #
Pin Name
Pin #
Pin Name
SER0
P129
SER0_TX
W25
UART2_TXD
SER0_TXD
Asynchronous serial port data out
P130
SER0_RX
AB28
UART2_RXD
SER0_RXD
Asynchronous serial port data in
P131
SER0_RTS#
AB26
UART2_RTS#
SER0_RTS
Request to Send handshake line for
SER0
P132
SER0_CTS#
AA25
UART2_CTS#
SER0_CTS
Clear to Send handshake line for
SER0
SER1
P134
SER1_TX
R3
ULPI_DATA0
SER1_TXD
Asynchronous serial port data out
P135
SER1_RX
V1
ULPI_DATA1
SER1_RXD
Asynchronous serial port data in
SER2
P136
SER2_TX
AC27
UART3_TXD
SER2_TXD
Asynchronous serial port data out
P137
SER2_RX
W27
UART3_RXD
SER2_RXD
Asynchronous serial port data in
P138
SER2_RTS#
AB29
UART3_RTS#
SER2_RTS
Request to Send handshake line for
SER2
P139
SER2_CTS#
W29
UART3_CTS#
SER2_CTS
Clear to Send handshake line for
SER2
SER3
P140
SER3_TX
M2
ULPI_CLK
SER3_TXD
Asynchronous serial port data out
P141
SER3_RX
M4
ULPI_DIR
SER3_RXD
Asynchronous serial port data in