Toradex Verdin, Manual

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Verdin Carrier Board Design Guide
Preliminary
– Subject to Change
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2.10.1
UART Signals
Verdin
Pin Verdin
Signal Name
I/O Type
Power
Rail
Description
129 UART_1_RXD I CMOS 1.8V Received Data of general purpose UART_1
131 UART_1_TXD O CMOS 1.8V Transmitted Data of general purpose UART_1
137 UART_2_RXD I CMOS 1.8V Received Data of general purpose UART_2
139 UART_2_TXD O CMOS 1.8V Transmitted Data of general purpose UART_2
147 UART_3_RXD I CMOS 1.8V Received Data for main OS debug UART_3
149 UART_3_TXD O CMOS 1.8V Transmitted Data for main OS debug UART_3
Table 22: "Always Compatible" UART Signals
Verdin
Pin Verdin
Signal Name
I/O Type
Power
Rail
Description
133 UART_1_RTS O CMOS 1.8V Request to Send of general purpose UART_1
135 UART_1_CTS I CMOS 1.8V Clear to Send of general purpose UART_1
141 UART_2_RTS O CMOS 1.8V Request to Send of general purpose UART_2
143 UART_2_CTS I CMOS 1.8V Clear to Send of general purpose UART_2
151 UART_4_RXD I CMOS 1.8V Received Data for real time core debug UART_4
153 UART_4_TXD O CMOS 1.8V Transmitted Data for real time core debug UART_4
Table 23: "Reserved" UART Signals
2.10.2
Reference Schematics
2.10.2.1 RS232 Reference Schematics
The RS232 interface can be classified as Data Terminal Equipment (DTE) or Data Communication
Equipment (DCE). This classification is inherited from the usage of the interface for modems. The
signal direction of these modes is different. Some Verdin modules might allow changing the mode
and therefore also the data direction, but this is not a mandatory requirement. According to the
Verdin specifications, the interface is intent to be used in the DTE configuration.
Signal Name Usage
DTE Direction
(Verdin
standard)
DCE Direction
UART_1_RXD Received Data Data from DCE to DTE Input Output
UART_1_TXD Transmitted Data Data from DTE to DCE Output Input
UART_1_RTS Request to Send
DTE request to DCE to be prepared to
receive data
Output Input
UART_1_CTS Clear to Send DCE indicates ready to accept data Input Output
Table 24: RS232 Signal Modes