單片機電子萬年歷系統的設計與研究(編輯修改稿)

　

【文章內容簡介】 精心指導，同時還在思想、生活上給我以無微不至的關懷，在此謹向 張 老師致以誠摯的謝意和崇高的敬意。我還要感謝在一起愉快的度過畢業論文小組的同學們，正是由于你們的幫助和支持，我才能克服一個一個的困難和疑惑，直至 畢業設計 的順利完成。 同時，我要感謝電氣工程系的各位老師，正是由于他們的傳道、授業、解 惑，讓我學到了專業知識，并從他們身上學到了如何求知治學、如何為人處事。另外，感謝電氣工程系 10 屆同學的幫助和勉勵。同窗之誼和手足之情，我將終生難忘！路漫漫其修遠兮，吾將上下而求索。我愿在未來的學習和工作過程中，以更加豐厚的成果來答謝曾經關心、幫助和支持過我的所有領導、老師、同學、和朋友。 在 畢業設計 即將完成之際，我的心情無法平靜，從開始進入課題到論文的順利完成，有多少可敬的師長、同學、朋友給了我無言的幫助，在這里請接受我誠摯的謝意 ! 最后 ， 我要感謝培養我長大含辛茹苦的父母，謝謝你們 ! 陜西理工學院畢業設計 第 16 頁 共 42 頁 參考文獻 ［ 1］ 華成英 .模擬電子技術基礎 .高等教育出版社 ,2020 ［ 2］ 閻 石 .數字電子技術基礎 .高等教育出版社 ,2020 ［ 3］ 邱關源 .電路 .高等教育出版 ,2020 ［ 4］ 何立民 .單片機原理應用與接口技術 .北京航空航天大學出版社 ,2020 ［ 5］ 譚浩強 .C 語言程序設計（第三版） .清華大學出版社 ,2020 ［ 6］ 李建忠 .單片微型機原理與應用 .西安電子科技大學出版社 ,2020. ［ 7］ 李增國 .傳感器與檢測技術 .北京航空航天大學出版社 .2020. ［ 8］ 房小翠 ,王金鳳 .單片微型計算機與機電接口技術 .北京國防工業出版社 ,2020. ［ 9］ 孫育才 .ATMEL 新型 AT89S52 系列單片機及其應用 .清華大學出版社 ,2020. 陜西理工學院畢業設計 第 17 頁 共 42 頁 AT89S52 英文資料 Description The AT89s52 is a lowpower, highperformance CMOS 8bit microputer with 8K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s highdensity nonvolatile memory technology and is patible with the industrystandard 80C51 and 80C52 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 Flash on a monolithic chip, the Atmel AT89s52 is a powerful microputer which provides a highlyflexible and costeffective solution to many embedded control applications. Pin Configurations The AT89s52 provides the following standard features: 8K bytes of Flash, 256 bytes of RAM, 32 I/O lines, three 16bittimer/counters, a sixvector twolevel interrupt architecture, a fullduplex 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 selectable 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 contents but freezes the oscillator, disabling all other chip functions until the next hardware reset. 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 internalpullups. 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. 陜西理工學院畢業設計 第 18 頁 共 42 頁 Port 1 also receives the loworder address bytes during Flash programming and verification. Port Pin Alternate Functions T2(external count input to Timer/Counter2) T2EX(Timer/Counter2 capture/reload trigger and direction control) 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 used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL ) because of the internal pullups. Port 2 emits the highorder address byte during fetches from external program memory and during accesses to external data memory that use 16bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pullups when emitting 1s. During accesses to external data memory that use 8bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the highorder address bits and some control signals during Flash programming and verification. 陜西理工學院畢業設計 第 19 頁 共 42 頁 Port 3 Port 3 is an 8bit bidirectional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL ) because of the pullups. Port 3 also serves the functions of various special features of the AT89C51, as shown in the following table. Port 3 also receives some control signals for Flash programming and verification. Port Pin Alternate Functions RXD(serial input port) TXD(serial output port) INT0(external interruput0) INT1(external interruput1) T0(timer 0 external input) T1(timer 1 external input) WR(external data memory write strode) RD(external data memory read strobe) RST Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device. ALE/PROG Address Latch Enable is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse in