【正文】 882002 Keil Elektronik GmbH and Keil Software, Inc.。 : This code is executed after processor reset.。 To translate this file use A51 with the following invocation:。 A51 。 To link the modified file to your application use the following。 BL51 invocation:。 BL51 your object file list, controls。 Userdefined PowerOn Initialization of Memory。 With the following EQU statements the initialization of memory。 at processor reset can be defined:。 。 the absolute startaddress of IDATA memory is always 0IDATALEN EQU 80H 。 the length of IDATA memory in bytes.。XDATASTART EQU 0H 。 the absolute startaddress of XDATA memoryXDATALEN EQU 0H 。 the length of XDATA memory in bytes.。PDATASTART EQU 0H 。 the absolute startaddress of PDATA memoryPDATALEN EQU 0H 。 the length of PDATA memory in bytes.。 Notes: The IDATA space overlaps physically the DATA and BIT areas of the。 8051 CPU. At minimum the memory space occupied from the C51 。 runtime routines must be set to zero.。 Reentrant Stack Initilization。 The following EQU statements define the stack pointer for reentrant。 functions and initialized it:。 Stack Space for reentrant functions in the SMALL model.IBPSTACK EQU 0 。 set to 1 if small reentrant is used.IBPSTACKTOP EQU 0FFH+1 。 set top of stack to highest location+1.。 Stack Space for reentrant functions in the LARGE model. XBPSTACK EQU 0 。 set to 1 if large reentrant is used.XBPSTACKTOP EQU 0FFFFH+1。 set top of stack to highest location+1.。 Stack Space for reentrant functions in the COMPACT model. PBPSTACK EQU 0 。 set to 1 if pact reentrant is used.PBPSTACKTOP EQU 0FFFFH+1。 set top of stack to highest location+1.。 Page Definition for Using the Compact Model with 64 KByte xdata RAM。 The following EQU statements define the xdata page used for pdata。 variables. The EQU PPAGE must conform with the PPAGE control used。 in the linker invocation.。PPAGEENABLE EQU 0 。 set to 1 if pdata object are used.。PPAGE EQU 0 。 define PPAGE number.。PPAGE_SFR DATA 0A0H 。 SFR that supplies uppermost address byte。 (most 8051 variants use P2 as uppermost address byte)。 Standard SFR Symbols ACC DATA 0E0HB DATA 0F0HSP DATA 81HDPL DATA 82HDPH DATA 83H NAME C_STARTUP?C_C51STARTUP SEGMENT CODE?STACK SEGMENT IDATA RSEG STACK DS 1 EXTRN CODE (?C_START) PUBLIC C_STARTUP CSEG AT 0x8000?C_STARTUP: LJMP STARTUP1 RSEG C_C51STARTUPSTARTUP1:IF IDATALEN 0 MOV R0,IDATALEN 1 CLR AIDATALOOP: MOV @R0,A DJNZ R0,IDATALOOPENDIFIF XDATALEN 0 MOV DPTR,XDATASTART MOV R7,LOW (XDATALEN) IF (LOW (XDATALEN)) 0 MOV R6,(HIGH (XDATALEN)) +1 ELSE MOV R6,HIGH (XDATALEN) ENDIF CLR AXDATALOOP: MOVX @DPTR,A INC DPTR DJNZ R7,XDATALOOP DJNZ R6,XDATALOOPENDIFIF PPAGEENABLE 0 MOV PPAGE_SFR,PPAGEENDIFIF PDATALEN 0 MOV R0,LOW (PDATASTART) MOV R7,LOW (PDATALEN) CLR APDATALOOP: MOVX @R0,A INC R0 DJNZ R7,PDATALOOPENDIFIF IBPSTACK 0EXTRN DATA (C_IBP) MOV C_IBP,LOW IBPSTACKTOPENDIFIF XBPSTACK 0EXTRN DATA (?C_XBP) MOV C_XBP,HIGH XBPSTACKTOP MOV C_XBP+1,LOW XBPSTACKTOPENDIFIF PBPSTACK 0EXTRN DATA (?C_PBP) MOV C_PBP,LOW PBPSTACKTOPENDIF MOV SP,?STACK1。 This code is required if you use with Banking Mode 4。 EXTRN CODE (?B_SWITCH0)。 CALL B_SWITCH0 。 init bank mechanism to code bank 0 LJMP C_START END鬧鈴的：ORG 8000H JMP MAIN ORG 800BH JMP INTT0 ORG 8100H MAIN: MOV SP,60H MOV TMOD,01H SETB ET0 SETB EA SETB TR0START0: SETB MOV 30H,00HNEXT: MOV A,30H MOV DPTR,TABLE MOVC A,@A+DPTR MOV R2,A JZ ENDD ANL A,0FH MOV R5,A MOV A,R2 SWAP A ANL A,0FH JNZ SING CLR TR0 JMP D1SING: DEC A MOV 22H,A RL A MOV DPTR,TABLE1 MOVC A,@A+DPTR MOV TH0,A MOV 21H,A MOV A,22H RL A INC A MOVC A,@A+DPTR MOV TL0,A MOV 20H,A SETB TR0D1: CALL DELAY INC 30H JMP NEXTENDD: CLR TR0 JMP START0INTT0: PUSH PSW PUSH ACC MOV TL0,20H MOV TH0,21H CPL POP AC