电气电子专业单片机外文翻译.doc

AT89C51

Description

The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K

bytes of Flash programmable and erasable read only memory (PEROM). The device is

manufactured using Atmel’s high-density nonvolatile memory technology and is compatible

The AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of

RAM, 32 I/O lines, two 16-bit timer/counters, a five 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 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 Power-down 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.

programverification. External pullups are required during programverification.

Port 1 is an 8-bit bi-directional 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