uart_dma_rb_transfer#
Overview#
The uart_dma ring buffer example shows how to use uart driver with DMA:
In this example, one uart instance connect to PC through uart, the board will send back all characters that PC send to the board. And data from PC will be firstly stored to a ring buffer using DMA methord, and than application will read the ring buffer in a certain time, such as 10ms. While data has already be stored in the ring buffer, routine will send them back.
And the ring buffer is achieved based on the DMA’s source address modulo feature, the base address should be aligned to a 0-modulo-boundary.
Supported Boards#
FRDM-K32L2B
Hardware requirements
Mini USB cable
FRDM-K32L2B board
Personal Computer
USB to Com Converter
Board settings
Connect pin:
RX of USB2COM to J1_6
TX of USB2COM to J2-4
GND of USB2COM to J2-14
Prepare the Demo
Connect USB to Com Converter between the PC host and the port on the board.
Open a serial terminal on PC for serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Reset the SoC and run the project.
Running the demo
When the demo runs successfully, the log would be seen on the UART Terminal port which connected to the USB2COM like:
UART DMA ring buffer example
Board will send back received data
FRDM-MCXC242
Hardware requirements
Mini USB cable
USB to TTL converter
FRDM-MCXC242 board
Personal Computer
Board settings
Connect the USB to TTL converter to FRDM-MCXC242 board. FRDM-MCXC242 UART pins:
TX of USB2COM to J1-5
RX of USB2COM to J1-7
GND of USB2COM to J2-14
Prepare the Demo
Connect a mini USB cable between the PC host and the OpenSDA USB port on the board.
Connect the USB to TTL converter to PC host.
Open a serial terminal on PC for the USB to TTL converter with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Reset the SoC and run the project.
Running the demo
When the demo runs successfully, the log would be seen on the UART Terminal port which connected to the USB2COM like:
UART DMA ring buffer example
Board will send back received data
FRDM-MCXC444
Hardware requirements
Type-C USB cable
FRDM-MCXC444 board
Personal Computer
USB to Com Converter
Board settings
Connect pin:
RX of USB2COM to J1_6
TX of USB2COM to J2-4
GND of USB2COM to J2-14
Prepare the Demo
Connect USB to Com Converter between the PC host and the port on the board.
Open a serial terminal on PC for serial device with these settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Reset the SoC and run the project.
Running the demo
When the demo runs successfully, the log would be seen on the UART Terminal port which connected to the USB2COM like:
UART DMA ring buffer example
Board will send back received data
TWR-KM35Z75M
Hardware requirements
Micro/Micro USB cable
TWR-KM35Z75M board
Personal Computer
Board settings
No special settings are required.
Prepare the Demo
Connect a USB cable between the host PC and the OpenSDA USB port on the target board.
Open a serial terminal with the following settings:
115200 baud rate
8 data bits
No parity
One stop bit
No flow control
Download the program to the target board.
Reset the SoC and run the project.
Running the demo
When the example runs successfully, the following message is displayed in the terminal:
UART DMA ring buffer example
Board will send back received data