外文翻译---采用高性能的静态80C51设计的单片机.docx

附录 III 外文资料

英文文献

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 with the industry-standard MCS-51 instruction set and pinout. The

on-chip Flash allows the program memory to be reprogrammed insystem or by a

conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU

with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer

* Fully Static Operation: 0 Hz to 24 MHz

* Three-level Program Memory Lock

* 128 x 8-bit Internal RAM

* 32 Programmable I/O Lines

* Two 16-bit Timer/Counters

* Six Interrupt Sources

* Programmable Serial Channel

* Low-power Idle and Power-down Modes

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

Pin Description

VCC

Supply voltage.

GND

Ground.

Port 0

Port 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 may also be configured to be the multiplexed loworder address/data bus during

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 (I ) because of the

internal pullups.

Port 1 also receives the low-order address bytes during Flash programming and

verification.

Port 2

Port 2 is an 8-bit bi-directional 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

Port 2 also receives the high-order address bits and some control signals during Flash

Port 3

Port 3 is an 8-bit bi-directional 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 (I ) because of the pullups.

Port 3 also serves the functions of various special features

P3.0 RXD (serial input port)

P3.3 INT1 (external interrupt 1)

P3.4 T0 (timer 0 external input)

P3.5 T1 (timer 1 external input)

P3.6 WR (external data memory write strobe)

P3.7 RD (external data memory read strobe)

Port 3 also receives some control signals for Flash pro-

gramming and verification.

RST

Reset input. A high on this pin for two machine cycles while the oscillator is running

resets the device.

ALE/PROG