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The ASSIGN command allows you to display and change the input and output sources for the specified serial channel.

Syntax Description
ASSIGN Display serial channel I/O assignments.
ASSIGN channel <inreg > outreg Change serial channel I/O assignments. Note the brackets around inreg and the trailing blank before the closing bracket.

The following table shows the supported channels and the default settings for the input (inreg) and output register (outreg).

Channel Default inreg Default outreg Description
COM1 None None COM port 1 on the PC.
COM2 None None COM port 2 on the PC.
COM3 None None COM port 3 on the PC.
COM4 None None COM port 4 on the PC.
WIN SIN or S1IN SOUT or S1OUT The Serial window.

The names of the input- and output registers (VTREGs) are defined by the CPU in use. All VTREGs can be listed with the command DIR VTREG.

The baudrate and other serial port parameters must be set with the command MODE.

>ASSIGN                     /* Display serial assignment                */
  WIN: <S0IN >S0OUT         /* S0IN provides serial input &             */
                            /* S0OUT provides serial output             */
>ASSIGN WIN <S1IN >S1OUT    /* Assign S1IN & S1OUT to the Serial window */
>ASSIGN                     /* And display the assignment               */

>ASSIGN COM1 < SIN > SOUT   /* Assign SIN & SOUT to COM1                */


  • The ASSIGN command cannot be used when debugging on target hardware.
  • The PC serial port (COM port) supports only up to 8 data bits. Therefore, it is impossible to generate more then 8 data bits, as it is possible on some microcontroller UART interfaces.
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