Expressions Example

EXTRN CODE (CLAB)                 ; entry in CODE space
EXTRN DATA (DVAR)                 ; variable in DATA space

MSK     EQU   0F0H                ; define a symbol to replace 0xF0
VALUE   EQU   MSK - 1             ; another constant symbolic value

?PR?FOO SEGMENT CODE
        RSEG  ?PR?FOO

ENTRY:  MOV  A,#40H               ; load register with constant
        MOV  R5,#VALUE            ; load constant symbolic value
        MOV  R3,#(0x20 AND MASK)  ; examples for calculations
        MOV  R7,#LOW (VALUE + 20H)
        MOV  R6,#1 OR (MSK SHL 4)

        MOV  R0,DVAR+20           ; load content from address DVAR+20
        MOV  R1,#LOW (CLAB+10)    ; load low byte of address CLAB+10
;
        MOV  R5,80H               ; load DATA addr. 80H (= SFR P0) to R5
        SETB 20H.2                ; set bit at 20H.2 (short address)

        END