AXEL Lite SOM/AXEL Lite Evaluation Kit/Interfaces and Connectors/UARTs
| History | |||
|---|---|---|---|
| Version | Issue Date | Notes | |
| Oct 2020 | First DESK release | ||
| 1.0.1 | Apr 2022 | Add GPIO setting reference | |
Contents
UARTs interface[edit | edit source]
Description[edit | edit source]
The UARTs interface available on the Evaluation Kit are mapped to the following connectors:
- J25 is a 6x1x2.54mm horizontal socket header for the UART4 port. This is a Digilent Pmod™ Compatible connector for the UART Pmod™ Compatiblemodule (6-Pin Pmod™ Compatible Connector Digilent Pmod™ Interface Specification Type 4 UART)
- J21 is a standard DB9 male connector for the configurable UART5 port. The board provides some configuration options for the selection of the UART mode (RS232/RS422/RS485 with auto-direction)
Signals[edit | edit source]
The following tables describes the interface signals
UART4[edit | edit source]
| Pin# | SOM Pin# | Pin name | Pin function | Pin Notes |
|---|---|---|---|---|
| 1 | J10.50 | PMOD_A0 | Clear to send | |
| 2 | J10.89 | PMOD_A1 | Transmit data | |
| 3 | J10.91 | PMOD_A2 | Receive data | |
| 4 | J10.40 | PMOD_A3 | Request to send | |
| 5 | - | DGND | Ground | |
| 6 | - | 3V3 | +3.3 V |
UART5[edit | edit source]
| Pin# | SOM Pin# | Pin name | RS-232 | RS-422 | RS-485 |
|---|---|---|---|---|---|
| 1 | - | Not connected | Not connected | Not connected | Not connected |
| 2 | J10.95 | UART5_A | UART5 receive line | UART5_A | UART5_A |
| 3 | J10.93 | UART5_Y | UART5 transmit line | UART5_Y | UART5_A |
| 4 | - | Not connected | Not connected | Not connected | Not connected |
| 5 | - | DGND | Ground | Ground | Ground |
| 6 | - | Not connected | Not connected | Not connected | Not connected |
| 7 | J10.105 | UART5_Z | UART5 Request To Send | UART5_Z | UART5_B |
| 8 | J10.107 | UART5_B | UART5 Clear To Send | UART5_B | UART5_B |
| 9 | - | Not connected | Not connected | Not connected | Not connected |
The J19 and J20 jumpers are used to configure the UART mode, as reported below:
| Jumper | RS232 mode | RS422 mode | RS485 mode |
|---|---|---|---|
| 1-3 | open | open | closed |
| 5-7 | open | closed | open |
| 9-11 | open | closed | open |
| 2-4 | open | open | closed |
| 6-8 | open | closed | closed |
| 10-12 | open | closed | closed |
| 13-15 | open | open | closed |
| 14-16 | open | open | closed |
Device mapping[edit | edit source]
- UART4 is mapped to
/dev/ttymxc3device in Linux - UART5 is mapped to
/dev/ttymxc4device in Linux
Device usage[edit | edit source]
- UART4 can be used with a PMOD adapter or with a TTL peripheral
- UART5 is a MultiProtocol that support (after harware Jumper configuration) the RS232, RS4222 or RS485 protocols. The related device tree file has to be properly configured too for enabling the GPIO transceiver configuration, see Configuring the RS232/RS485 mode
