Detailed reference for the ANDWF instruction in PIC18 ISA.
AND the contents of WREG with file register f.
d = 0 → result is stored in WREG.d = 1 → result is stored back into register f.a = 0 → Access‑bank addressing.a = 1 → Banked addressing.; d=0, a=0 → result in WREG, Access bank
ANDWF 0x21, 0, 0 ; W = 0x21 & W; d=0, a=0 → result in WREG, Access bank
ANDWF 0x21, 0, 0 ; W = 0x21 & W; d=0, a=1 → result in WREG, Banked address
ANDWF 0x21, 0, 1 ; W = 0x21 & W; d=0, a=1 → result in WREG, Banked address
ANDWF 0x21, 0, 1 ; W = 0x21 & W; d=1, a=0 → result back to file register, Access bank
ANDWF 0x21, 1, 0 ; 0x21 = 0x21 & W; d=1, a=0 → result back to file register, Access bank
ANDWF 0x21, 1, 0 ; 0x21 = 0x21 & W; d=1, a=1 → result back to file register, Banked address
ANDWF 0x21, 1, 1 ; 0x21 = 0x21 & W; d=1, a=1 → result back to file register, Banked address
ANDWF 0x21, 1, 1 ; 0x21 = 0x21 & W; Load literal into WREG then AND, result in WREG (Access bank)
MOVLW 0x0F
ANDWF 0x21, 0, 0 ; W = 0x21 & 0x0F; Load literal into WREG then AND, result in WREG (Access bank)
MOVLW 0x0F
ANDWF 0x21, 0, 0 ; W = 0x21 & 0x0F