【正文】 (3):7274. [21] [M].北京：高等教育出版社,2003.匯編語言程序ORG 0000HLJMP STARTSTART:CLR AMOV P2,AMOV R0,70HMOV R2,0DHLOOPMEM:MOV R0,AINC R0DJNZ R2,LOOPMEMMOV 20H,00HMOV A,0FFHMOV P0,AMOV P1,AMOV P3,AMAIN:LCALL TESTLCALL DISPLAYAJMP MAINNOPNOPNOPLJMP STARTDISPLAY:JB 00H,DISP11MOV R3,08HMOV R0,70HMOV 7BH,00HDISLOOP1:LCALL TUNBCDMOV R2,0FFHDISLOOP2:LCALL DISPLCALL KEYWORK1DJNZ R2,DISLOOP2INC R0INC 7BHDJNZ R3,DISLOOP1RETDISP11:MOV A,7BHSUBB A,01HMOV 7BH,AADD A,70HMOV R0,ADISLOOP11:LCALL TUNBCDMOV R2,0FFHDISLOOP22:LCALL DISPLCALL KEYWORK2DJNZ R2,DISLOOP22INC 7BHRETTUNBCD:MOV A,R0MOV B,51HDIV ABMOV 7AH,AMOV A,BCLR F0SUBB A,1AHMOV F0,CMOV A,10HMUL ABMOV B,51DIV ABJB F0,LOOP2ADD A,5LOOP2:MOV 79H,AMOV A,BCLR F0SUBB A,1AHMOV F0,CMOV A,10HMUL ABMOV B,51DIV ABJB F0,LOOP3ADD A,5LOOP3:MOV 78H,ARETDISP:MOV R1,78HMOV R5,0FEHPLAY:MOV P1,0FFHMOV A,R5ANL P3,AMOV A,R1MOV DPTR,TABMOVC A,A+DPTRMOV P1,AJB ,PLAY1CLR PLAY1:LCALL DL1MSINC R1MOV A,P3JNB ,ENDOUTRL AMOV R5,AMOV P3,0FFHAJMP PLAYENDOUT:MOV P3,0FFHMOV P1,0FFHRETTAB: DB 0C0H,0F9H,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H,0FFHDL10MS:MOV R6,0D0HDL1:MOV R7,10HDL2:DJNZ R7,DL2DJNZ R6,DL1RETDL1MS:MOV R4,0FFHDL3:DJNZ R4,DL3MOV R4,0FFHDL4:DJNZ R4,DL4RETTEST:CLR AMOV P2,AMOV R0,70HMOV R7,08HLCALL TESTARTWAIT:JB ,MOVDAJMP WAITTESTART:SETB NOPNOPCLR SETB NOPNOPCLR NOPNOPNOPNOPRETMOVD:SETB MOV A,P0MOV R0,ACLR INC R0MOV A,P2INC AMOV P2,ACJNE A,08H,TESTENDTESTEND:JC TESTCONCLR AMOV P2,AMOV A,0FFHMOV P0,AMOV P1,AMOV P2,ARETTESTCON:LCALL TESTARTLJMP WAITKEYWORK1:JNB ,KEY1KEYOUT:RETKEY1:LCALL DISPJB ,KEYOUTWAIT11:JNB ,WAIT12CPL 00HMOV R2,0AHMOV R3,01HRETWAIT12:LCALL DISPAJMP WAIT11KEYWORK2:JNB ,KEY1JNB ,KEY2RETKEY2:LCALL DISPJB ,KEYOUTWAIT22:JNB ,WAIT21INC 7BHMOV A,7BHCJNE A,08H,KEYOUT11KEYOUT11:JC KEYOUT1MOV 7BH,00HKEYOUT1:RETWAIT21:LCALL DISPAJMP WAIT22END外文資料AT89S52Features? Compatible with MCS51 Products? 8K Bytes of InSystem Programmable (ISP) Flash Memory – Endurance: 10,000 Write/Erase Cycles? to Operating Range? Fully Static Operation: 0 Hz to 33 MHz? Threelevel Program Memory Lock ? 256 x 8bit Internal RAM ? 32 Programmable I/O Lines ? Three 16bit Timer/Counters ? Eight Interrupt Sources? Full Duplex UART Serial Channel ? Lowpower Idle and Powerdown Modes? Interrupt Recovery from Powerdown Mode ? Watchdog Timer ? Dual Data Pointer ? Poweroff Flag ? Fast Programming Time ? Flexible ISP Programming (Byte and Page Mode) ? Green (Pb/Halidefree) Packaging Option1. DescriptionThe AT89S52 is a lowpower, highperformance CMOS 8bit microcontroller with 8K bytes of insystem programmable Flash memory. The device is manufactured using Atmel’s highdensity nonvolatile memory technology and is patible with the industrystandard 80C51 instruction set and pinout. The onchip Flash allows the program memory to be reprogrammed insystem or by a conventional nonvolatile memory programmer. By bining a versatile 8bit CPU with insystem programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highlyflexible and costeffective solution to many embedded control applications. The AT89S52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16bit timer/counters, a sixvector twolevel interrupt architecture, a full duplex serial port, onchip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectabe power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Powerdown mode saves the RAM clontents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.2. Pin Description VCC ：Supply voltage. GND ：Ground. Port 0：Port 0 is an 8bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs. Port 0 can also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode, P0 has internal pullups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pullups are required during program verification. Port 1：Port 1 is an 8bit bidirectional I/O port with internal pullups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups. In addition, and can be configured to be the timer/counter 2 external count input () and the timer/counter 2 trigger input (), respectively, as shown in the following table. Port 1 also receives the loworder address bytes during Flash programming and verification.Port PinAlternate FunctionsT2 (external count input to Timer/Counter 2), clockoutT2EX (Timer/Counter 2 capture/reload trigger and direction control)MOSI (used for InSystem Programming)MISO (used for InSystem Programming)SCK (used for InSystem Programming) Port 2：Port 2 is an 8bit bidirectional I/O port with internal pullups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pullups and can be