First off, you write a 'putchar' subroutine that takes a value in ACC and xmits through the UART.
Then you either:

    mov A,#0x7E
    call putchar
    mov A,#0x01
    call putchar
    ...

 

Or you write another function that will xmit N bytes starting at address in DPTR.
e.g. using your putchar subroutine.

    ...
    mov DPTR,#address    ;where your bytes live
    mov R0,#7            ;how many bytes
    call putblock
    ...
putblock:                
    ...                  ;call putchar for each byte
    ret

 

You should see many examples of this sort of subroutine. Of course you can pass your parameters in different ways. Does not have to be DPTR, ACC, R0.

Remember to test for the TX buffer being empty before you can write a byte to the UART.

Andy asked "Why ASM?"
Learning how to do this in C would mean you could do something similar with and type of chip. The 'design' process is the same.

David.