DsPIC Block/UART Configuration

Block UART Configuration

UART Dialog, Tab General

The UART Configuration block set the parameters for the UART. Each UART has one Receive Rx pin and one Transmit pin Tx. The UART parameters are commmon for Rx and Tx of the same UART. The number or UART available depend on the Microcontroller used ( defined in the master block). Following parameters are fixed :

• 1 stop bit
• 8 bits data
• no parity
• no flow control

Related blocks : Block/UART_Configuration Block/Rx_Input Block/Tx_Output Block/Tx_Output_Multiplexed_For_Matlab-Labview Block/Interface_Tx-Matlab

Dialog Box Parameters

n° UART

UART to be used

Main

Baud (kb/s)

UART Speed you want to use. The exact speed will usually not be reach. An error below 4% usually gives no transmission errors. Check the error speed before use.

Tx Rx Alternativ

Use the Alternative Tx and Rx pin of the microcontroller if available. Use default pin otherwise.

TXEN

Set the output pin TX active for transmitting serial data. This is automatically checked when a Tx or "Tx Output Multiplexed For Matlab Labview" is present.

Info

Gives following information : UxBRG register value. The real bit rate achieved by the microcontroller and the error in percent between the real bit rate and the requested bit rate. The max Byte/Step is the maximum number of byte that can physically be sent during one diagram time step. If your schematic try to send more data through the UART, somme data will not be sent or the real time constraint will be violated (ie, the time step will be longer than expected).

Tx Interrupt

UART Dialog, Tab Tx

Tx Interrupt take place

The UART peripheral has an internal 4 bytes Transmit buffer. Activating the Tx interrupt virtually extend this buffer to the desired size. The complete buffer size is the sum of the Tx interrupt buffer size plus the UART buffer size (4). The Tx interrupt can take place :

• When the UART Peripheral Transmit buffer is empty
• When the UART Peripheral Transmit buffer has one empty space

Tx Interrupt Priority

Priority of the interrupt (1 is the lowest priority, 7 is the highest)

Tx Interrupt buffer size

Size of the circular buffer used by the interrupt. The total buffer size for the UART Tx peripheral is then the Tx Interrupt buffer size plus the 4 bytes internal peripheral buffer.

Rx Interrupt

UART Dialog, Tab Rx

Rx Interrupt take place

The UART peripheral has an internal 4 bytes Receive buffer. Activating the Rx interrupt virtually extend this buffer to the desired size. The complete buffer size is the sum of the Rx interrupt buffer size plus the UART buffer size (4). The Rx interrupt can take place :

• When the UART Peripheral Receive buffer is full (contains 4 bytes)
• When the UART Peripheral Receive buffer is 3/4 full (contains 3 bytes)
• When the UART Peripheral Receive buffer contain 1 byte (receive 1 byte)

Rx Interrupt Priority

Priority of the interrupt (1 is the lowest priority, 7 is the highest)

Rx Interrupt buffer size

Size of the circular buffer used by the interrupt. The total buffer size for the UART Rx peripheral is then the Rx Interrupt buffer size plus the 4 bytes internal peripheral buffer.

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