AXEL Lite SOM/AXEL Lite Evaluation Kit/Interfaces and Connectors/UARTs
| History | |||
|---|---|---|---|
| Version | Issue Date | Notes | |
| 1.0.0 | Oct 2020 | First DESK release | |
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.
