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1、毕业设计(论文)英文资料翻译 学生姓名： 学 号： 1403134332 系 别： 机 电 系 专 业： 自动化 指导教师： 2007 年 5 月 18 日1AT89C51（8-bit Micro controller with 4K Bytes Flash）Features Compatible with MCS-51 Products 4K Bytes of In-System Reprogrammable Flash Memory Endurance: 1,000 Write/Erase Cycles Fully Static Operation: 0 Hz to 12 MHz 256
2、x 8-bit Internal RAM 32 Programmable I/O Lines two 16-bit Timer/Counters five Interrupt Sources Programmable Serial Channel Low-power Idle and Power-down ModesDescriptionThe AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 8K bytes of Flash programmable and erasable read only m
3、emory (PEROM). The device is manufactured using Atmels high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 and 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory
4、 programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications.PinConfigurations The AT89C51 provides the following standard features: 4K
5、bytes of Flash, 256 bytes of RAM, 32 I/O lines, two 16-bittimer/counters, a six-vector two-level interrupt architecture, a full-duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two so
6、ftware 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 Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset
7、.Pin DescriptionVCCSupply voltage.GNDGround.Port 0Port 0 is an 8-bit open drain bi-directional 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 high impedance inputs. Port 0 can also be configured to be the multiplexed low o
8、rder address/data bus during accesses to external program and data memory. In this mode, P0 has internal pull ups. Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pull ups are required during program verification.Port 1Por
9、t 1 is an 8-bit bi-directional I/O port with internal pull ups. 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 pull ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will sou
10、rce current (IIL) because of the internal pull ups. In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively, as shown in the following table. Port 1 also receives the low-order address bytes
11、 during Flash programming and verification. Port 2Port 2 is an 8-bit bi-directional I/O port with internal pull ups. 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 pull ups and can be used as inputs. As inputs, Port
12、 2 pins that are externally being pulled low will source current (IIL) because of the internal pull ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX DPTR). In this application, Port 2
13、 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-order address bits and some control signals during Flash programming and verificat
14、ion.Port 3Port 3 is an 8-bit bi-directional I/O port with internal pull ups. 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 pull ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled
15、 low will source current (IIL) because of the pull ups. 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 PinAlternate FunctionsP3.0RXD(serial input port)P3.1TXD(serial output port)P3.2INTO(external interrupt 0)P3.3INT1(external interrupt 1)P3.4T0(timer 0 external input)P3.5T1(timer 1 external input)P3.6WR(external data memory write strobe)P3.7RD(external data memory read strobe)RSTReset input. A high on this pin for two machine cycles while the
