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B. Reserved Symbols

The Ax51 assembler uses predefined or reserved symbols that may not be redefined in your program. Reserved symbol names include instruction mnemonics, directives, operators, and register names. The following lists the reserved symbol names that are found in all Ax51 variants:

  • A
  • AB
  • ACALL
  • ADD
  • ADDC
  • AJMP
  • AND
  • ANL
  • AR0
  • AR1
  • AR2
  • AR3
  • AR4
  • AR5
  • AR6
  • AR7
  • BIT
  • BITADDRESSABLE
  • BLOCK
  • BSEG
  • C
  • CALL
  • CJNE
  • CLR
  • CMP
  • CODE
  • CPL
  • CSEG
  • DA
  • DATA
  • DB
  • DBIT
  • DEC
  • DIV
  • DJNZ
  • DPTR
  • DS
  • DSEG
  • DW
  • ELSE
  • ELSEIF
  • END
  • ENDIF
  • ENDM
  • ENDP
  • EQ
  • EQU
  • EXITM
  • EXTRN
  • GE
  • GT
  • HIGH
  • IDATA
  • IF
  • INBLOCK
  • INC
  • INPAGE
  • INSEG
  • IRP
  • IRPC
  • ISEG
  • JB
  • JBC
  • JC
  • JE
  • JG
  • JLE
  • JMP
  • JNB
  • JNC
  • JNE
  • JNZ
  • JSG
  • JSGE
  • JSL
  • JSLE
  • JZ
  • LCALL
  • LE
  • LJMP
  • LOCAL
  • LOW
  • LT
  • MACRO
  • MOD
  • MOV
  • MOVC
  • MOVX
  • MUL
  • NAME
  • NE
  • NOP
  • NOT
  • NUL
  • NUMBER
  • OR
  • ORG
  • ORL
  • OVERLAYABLE
  • PAGE
  • PC
  • POP
  • PUBLIC
  • PUSH
  • R0
  • R1
  • R2
  • R3
  • R4
  • R5
  • R6
  • R7
  • REPT
  • RET
  • RETIv
  • RL
  • RLC
  • RR
  • RRC
  • RSEG
  • SEG
  • SEGMENT
  • SET
  • SETB
  • SHL
  • SHR
  • SJMP
  • SUB
  • SUBB
  • SWAP
  • UNIT
  • USING
  • XCH
  • XCHD
  • XDATA
  • XOR
  • XRL
  • XSEG

The A51 assembler defines the following additional reserved symbols which are special function registers (SFR) of the classic 8051 MCU. These SFR definitions may be disabled using the NOMOD51 control statement. The predefined SFR symbols are reserved symbols and may not be redefined in your program.

  • AC
  • ACCv
  • B
  • CY
  • DPH
  • DPL
  • EA
  • ES
  • ET0
  • ET1
  • EX0
  • EX1
  • F0
  • IE
  • IE0
  • IE1
  • INT0
  • INT1
  • IT0
  • IT1
  • OV
  • P
  • P0
  • P1
  • P2
  • P3
  • PS
  • PSW
  • PT0
  • PT1
  • PX0
  • PX1
  • RB8
  • RD
  • REN
  • RI
  • RS0
  • RS1
  • RXD
  • SBUF
  • SCON
  • SM0
  • SM1
  • SM2
  • SP
  • T1
  • TB8
  • TCON
  • TF0
  • TF1
  • TH0
  • TH1
  • TI
  • TL0
  • TL1
  • TMOD
  • TO
  • TR0
  • TR1
  • TXD
  • WR

The AX51 assembler defines the following additional reserved symbols which comprise the additional instructions and registers of the Philips 80C51MX architecture.

  • AT
  • BYTE
  • BYTE0
  • BYTE1
  • BYTE2
  • BYTE3
  • CONST
  • DD
  • DSB
  • DSD
  • DSW
  • DWORD
  • ECALL
  • ECODE
  • EDATA
  • EJMP
  • EMOV
  • EPTR
  • ERET
  • EVEN
  • EXTERN
  • FAR
  • HCONST
  • HDATA
  • LABEL
  • LIT
  • MBYTE
  • NEAR
  • OFFS
  • PR0
  • PR1
  • PROC
  • WORD
  • WORD0
  • WORD2
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