CLEAR

CLEAR

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Action

Clear serial input or output buffer

 

 

Syntax

CLEAR bufname

 

 

Remarks

Bufname

Serial buffer name to clear.

 

SERIALIN, SERIALIN0 - COM1/UART0 input buffer

SERIALIN1 - COM2/UART1 input buffer

SERIALIN2 - COM3/UART2 input buffer

SERIALIN3 - COM4/UART3 input buffer

SERIALIN4 - COM5/UART4 input buffer

SERIALIN5 - COM6/UART5 input buffer

SERIALIN6 - COM7/UART6 input buffer

SERIALIN7 - COM8/UART7 input buffer

 

 

SERIALOUT,SERIALOUT0 - COM1/UART0 output buffer

SERIALOUT1 - COM2/UART1 output buffer

SERIALOUT2 - COM3/UART2 output buffer

SERIALOUT3 - COM4/UART3 output buffer

SERIALOUT4 - COM5/UART4 output buffer

SERIALOUT5 - COM6/UART5 output buffer

SERIALOUT6 - COM7/UART6 output buffer

SERIALOUT7 - COM8/UART7 output buffer

 

 

When you use buffered serial input or buffered serial output, you might want to clear the buffer.

While you can make the head pointer equal to the tail pointer, an interrupt could be active which might result in an update of the buffer variables, resulting in an unexpected result.

The CLEAR statement will reset the head and tail pointers of the ring buffer, and it will set the buffer count variable to 0. The buffer count variable is new and introduced in 1.11.8.3. It counts how many bytes are in the buffer.

The internal buffercount variable is named _RS_BUFCOUNTxy , where X is R for Receive, and W for Write, and y is 0 for the first UART, and 1 for the second UART.

 

 

See also

CONFIG SERIALIN, CONFIG SERIALOUT

 

 

ASM

Calls _BUF_CLEAR from MCS.LIB

 

 

Example

CLEAR SERIALIN