?? l51_bank.a51
字號:
MOV A,R3
DEC A
ANL A,#3FH
ENDIF
?B_SWITCHBANK_A:
MOV DPTR,#switch_tab
MOVC A,@A+DPTR
?B_RESTORE_BANK: ; entry for RTX-51/XBANKING bank restore
MOV DPTR,#?BANK?SWITCH
JMP @A+DPTR
S_ENTRY MACRO N
DB LOW ?B_SWITCH&N
ENDM
switch_tab:
CNT SET 0
REPT ?B_NBANKS
S_ENTRY %CNT
CNT SET CNT+1
ENDM
ENDIF ; close block IF ?B_MODE = 4 *******************************************
IF ?B_VAR_BANKING ;***********************************************************
;******************************************************************************
; *
; THEORY OF OPERATION *
; ------------------- *
; This section describes how the extended LX51 linker/locater manages the *
; extended address spaces that are addressed with the new C51 memory types *
; 'far' and 'far const'. The C51 Compiler uses 3 byte pointer generic *
; pointer to access these memory areas. 'far' variables are placed in the *
; memory class HDATA and 'far const' variables get the memory class 'HCONST'. *
; The LX51 linker/locater allows you to locate these memory classes in the *
; logical 16 MBYTE CODE or 16 MBYTE XDATA spaces. *
; *
; The memory access itself is performed via eight different subroutines that *
; can be configured in this assembler module. These routines are: *
; ?C?CLDXPTR, ?C?CSTXPTR ; load/store BYTE (char) in extended memory *
; ?C?ILDXPTR, ?C?ISTXPTR ; load/store WORD (int) in extended memory *
; ?C?PLDXPTR, ?C?PSTXPTR ; load/store 3-BYTE PTR in extended memory *
; ?C?LLDXPTR, ?C?LSTXPTR ; load/store DWORD (long) in extended memory *
; *
; Each function gets as a parameter the memory address with 3 BYTE POINTER *
; representation in the CPU registers R1/R2/R3. The register R3 holds the *
; memory type. The C51 compiler uses the following memory types: *
; *
; R3 Value | Memory Type | Memory Class | Address Range *
; -----------------------+--------------+-------------------------- *
; 00 | data/idata | DATA/IDATA | I:0x00 .. I:0xFF *
; 01 | xdata | XDATA | X:0x0000 .. X:0xFFFF *
; 02..7F | far | HDATA | X:0x010000 .. X:0x7E0000 *
; 80..FD | far const | HCONST | C:0x800000 .. C:0xFD0000 (see note) *
; FE | pdata | XDATA | one 256-byte page in XDATA memory *
; FF | code | CODE | C:0x0000 .. C:0xFFFF *
; *
; Note: the far const memory area is mapped into the banked memory areas. *
; *
; The R3 values 00, 01, FE and FF are already handled within the C51 run-time *
; library. Only the values 02..FE are passed to the XPTR access functions *
; described below. The AX51 macro assembler provides the MBYTE operator *
; that calculates the R3 value that needs to be passed to the XPTR access *
; function. AX51 Assembler example for using XPTR access functions: *
; MOV R1,#LOW (variable) ; gives LSB address byte of variable *
; MOV R1,#HIGH (variable) ; gives MSB address byte of variable *
; MOV R1,#MBYTE (variable) ; gives memory type byte of variable *
; CALL ?C?CLDXPTR ; load BYTE variable into A *
;******************************************************************************
PUBLIC ?C?CLDXPTR, ?C?CSTXPTR, ?C?ILDXPTR, ?C?ISTXPTR
PUBLIC ?C?PLDXPTR, ?C?PSTXPTR, ?C?LLDXPTR, ?C?LSTXPTR
?C?LIB_CODE SEGMENT CODE
RSEG ?C?LIB_CODE
IF ?B_MODE = 0 OR ?B_MODE = 1 ;*********************************************
; Define Helper Macros
; Shift Bank No in Accu to correct bit position
IF ?B_FIRSTBIT = 0
CONV_MSPC MACRO
ANL A,#LOW (MASK)
ENDM
ENDIF
IF ?B_FIRSTBIT = 1
CONV_MSPC MACRO
RL A
ANL A,#LOW (MASK SHL 1)
ENDM
ENDIF
IF ?B_FIRSTBIT = 2
CONV_MSPC MACRO
RL A
RL A
ANL A,#LOW (MASK SHL 2)
ENDM
ENDIF
IF ?B_FIRSTBIT = 3
CONV_MSPC MACRO
SWAP A
RR A
ANL A,#LOW (MASK SHL 3)
ENDM
ENDIF
IF ?B_FIRSTBIT = 4
CONV_MSPC MACRO
SWAP A
ANL A,#LOW (MASK SHL 4)
ENDM
ENDIF
IF ?B_FIRSTBIT = 5
CONV_MSPC MACRO
SWAP A
RL A
ANL A,#LOW (MASK SHL 5)
ENDM
ENDIF
IF ?B_FIRSTBIT = 6
CONV_MSPC MACRO
RR A
RR A
ANL A,#LOW (MASK SHL 6)
ENDM
ENDIF
IF ?B_FIRSTBIT = 7
CONV_MSPC MACRO
RR A
ANL A,#LOW (MASK SHL 7)
ENDM
ENDIF
ENDIF ; close block IF ?B_MODE = 0 OR ?B_MODE = 1 *************************
IF ?B_MODE = 0 ;**************************************************************
; Select Bank depending on value in R3
SEL_BNK MACRO SaveA
IF NOT NUL SaveA
PUSH ACC
ENDIF
CALL SELECT_BANK_R3
IF NOT NUL SaveA
POP ACC
ENDIF
ENDM
; Pop previous Bank and select it again
POP_BNK MACRO SaveA
LOCAL BNK_EA1
IF NOT NUL SaveA
MOV DPL,A
ENDIF
POP ACC ; bank information
ANL A,#?B_MASK
IF ?B_RTX = 1
JBC EA,BNK_EA1
ENDIF
ORL ?B_CURRENTBANK, #?B_MASK
ANL ?B_CURRENTBANK, A
IF NOT NUL SaveA
MOV A,DPL
ENDIF
RET
BNK_EA1: ; interrupts where enabled
IF ?B_RTX = 1
ORL ?B_CURRENTBANK, #?B_MASK
ANL ?B_CURRENTBANK, A
SETB EA ; enable interrupts again
IF NOT NUL SaveA
MOV A,DPL
ENDIF
RET
ENDIF
ENDM
SELECT_BANK_R3:
MOV A,R3
DEC A
CONV_MSPC
MOV DPL,R1
MOV DPH,R2
CJNE R3,#80H,SEL_BANK_LAB ; set CY
SEL_BANK_lab:
IF ?B_RTX = 1
JBC EA,SEL_BANK_EA1
ENDIF
ORL ?B_CURRENTBANK, #?B_MASK
ANL ?B_CURRENTBANK, A
RET
SEL_BANK_EA1: ; interrupts where enabled
IF ?B_RTX = 1
ORL ?B_CURRENTBANK, #?B_MASK
ANL ?B_CURRENTBANK, A
SETB EA ; enable interrupts again
RET
ENDIF
ENDIF ; close block IF ?B_MODE = 0 *******************************************
IF ?B_MODE = 1 ;***************************************************************
; Select Bank depending on value in R3
SEL_BNK MACRO SaveA
LOCAL lab
IF NOT NUL SaveA
PUSH ACC
ENDIF
CALL SELECT_BANK_R3
IF NOT NUL SaveA
POP ACC
ENDIF
ENDM
; Pop previous Bank and select it again
POP_BNK MACRO SaveA
IF NOT NUL SaveA
POP DPL
XCH A,DPL
PUSH DPL
ELSE
POP ACC
ENDIF
MOV DPTR,#?B_XDATAPORT
MOV ?B_CURRENTBANK,A
MOVX @DPTR,A
IF NOT NUL SaveA
POP ACC
ENDIF
RET
ENDM
SELECT_BANK_R3:
MOV A,R3
DEC A
CONV_MSPC
MOV DPTR,#?B_XDATAPORT
MOV ?B_CURRENTBANK,A
MOVX @DPTR,A
MOV DPL,R1
MOV DPH,R2
CJNE R3,#80H,SEL_BANK_LAB ; set CY
SEL_BANK_LAB:
RET
ENDIF ; close block IF ?B_MODE = 1 *******************************************
IF ?B_MODE = 4 ;**************************************************************
; Select Bank depending on value in R3
SEL_BNK MACRO SaveA
LOCAL lab
IF NOT NUL SaveA
PUSH ACC
ENDIF
CALL SELECT_BANK_R3
IF NOT NUL SaveA
POP ACC
ENDIF
MOV DPL,R1
MOV DPH,R2
CJNE R3,#80H,lab
lab:
ENDM
; Pop previous Bank and select it again
POP_BNK MACRO SaveA
IF NOT NUL SaveA
POP DPL
XCH A,DPL
PUSH DPL
CALL ?B_RESTORE_BANK
POP ACC
RET
ELSE
POP ACC
MOV DPTR,#?BANK?SWITCH
JMP @A+DPTR
ENDIF
ENDM
ENDIF ; close block IF ?B_MODE = 4 *******************************************
; CLDXPTR: Load BYTE in A via Address given in R1/R2/R3
?C?CLDXPTR: PUSH ?B_CURRENTBANK
SEL_BNK
JNC CLDCODE
MOVX A,@DPTR
SJMP RETURN_A
CLDCODE: CLR A
MOVC A,@A+DPTR
RETURN_A: POP_BNK 1
; CSTXPTR: Store BYTE in A via Address given in R1/R2/R3
?C?CSTXPTR: PUSH ?B_CURRENTBANK
SEL_BNK 1
JNC CSTCODE
MOVX @DPTR,A
CSTCODE: SJMP RETURN_A ; correct 10.5.2002
; ILDXPTR: Load WORD in A(LSB)/B(HSB) via Address given in R1/R2/R3
?C?ILDXPTR: PUSH ?B_CURRENTBANK
SEL_BNK
JNC ILDCODE
MOVX A,@DPTR
MOV B,A
INC DPTR
MOVX A,@DPTR
SJMP RETURN_A
ILDCODE: CLR A
MOVC A,@A+DPTR
MOV B,A
MOV A,#1
MOVC A,@A+DPTR
SJMP RETURN_A
; ISTXPTR: Store WORD in A(HSB)/B(LSB) via Address given in R1/R2/R3
?C?ISTXPTR: PUSH ?B_CURRENTBANK
SEL_BNK 1
JNC ISTCODE
MOVX @DPTR,A
INC DPTR
MOV A,B
MOVX @DPTR,A
ISTCODE: SJMP RETURN_NO_A
; PLDXPTR: Load PTR in R1/R2/R3 via Address given in R1/R2/R3
?C?PLDXPTR: PUSH ?B_CURRENTBANK
SEL_BNK
JNC PLDCODE
MOVX A,@DPTR
MOV R3,A
INC DPTR
MOVX A,@DPTR
MOV R2,A
INC DPTR
MOVX A,@DPTR
MOV R1,A
SJMP RETURN_NO_A
PLDCODE: CLR A
MOVC A,@A+DPTR
MOV R3,A
MOV A,#1
MOVC A,@A+DPTR
MOV R2,A
MOV A,#2
MOVC A,@A+DPTR
MOV R1,A
RETURN_NO_A: POP_BNK
; PSTXPTR: Store PTR in R0/A/B via Address given in R1/R2/R3
?C?PSTXPTR: PUSH ?B_CURRENTBANK
SEL_BNK 1
JNC PSTCODE
XCH A,B
MOVX @DPTR,A
INC DPTR
XCH A,B
MOVX @DPTR,A
INC DPTR
MOV A,R0
MOVX @DPTR,A
PSTCODE: SJMP RETURN_NO_A
; LLDXPTR: Load DWORD in R4/R5/R6/R7 via Address given in R1/R2/R3
?C?LLDXPTR: PUSH ?B_CURRENTBANK
SEL_BNK
JNC LLDCODE
MOVX A,@DPTR
MOV R4,A
INC DPTR
MOVX A,@DPTR
MOV R5,A
INC DPTR
MOVX A,@DPTR
MOV R6,A
INC DPTR
MOVX A,@DPTR
MOV R7,A
SJMP RETURN_NO_A
LLDCODE: CLR A
MOVC A,@A+DPTR
MOV R4,A
MOV A,#1
MOVC A,@A+DPTR
MOV R5,A
MOV A,#2
MOVC A,@A+DPTR
MOV R6,A
MOV A,#3
MOVC A,@A+DPTR
MOV R7,A
SJMP RETURN_NO_A
; LSTXPTR: Store DWORD in R4/R5/R6/R7 via Address given in R1/R2/R3
?C?LSTXPTR: PUSH ?B_CURRENTBANK
SEL_BNK
JNC LSTCODE
MOV A,R4
MOVX @DPTR,A
INC DPTR
MOV A,R5
MOVX @DPTR,A
INC DPTR
MOV A,R6
MOVX @DPTR,A
INC DPTR
MOV A,R7
MOVX @DPTR,A
LSTCODE: SJMP RETURN_NO_A
ENDIF ; close block IF ?B_VAR_BANKING ****************************************
END
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