单片机

an 8bit opendrain 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 high impedance inputs. Port 0 may also be

ventional programming. In a single chip, have clever 8 bits CPU and programmable Flash in the system, for many embedded control AT89S52 application system provides a highly flexible, efficient

smaller, pulse positive current can be bigger. Traffic signal control type The purpose of the traffic signal control are three: first,in time and space space intersection traffic in different

cation, it uses strong internal pullupswhen emitting 1s. During accesses to external data memory that use 8bit addresses, Port 2 emits the contents of the P2 Special Function 2 also receives the

pullups and can be used as inputs. As inputs,Port 2 pins that are externally being pulled low will source current, because of the internal 2 emits the highorder address byte during fetches from

stem。 in thermostat mode, user need to program to constitute the temperature control system. Two working mode can transform each other. The AT89C51 chip converts control mands and data received by

Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read Only Memories,

tirate threephase watthour meter based on AT89LV52. This multirate threephase watthour meter adopts AD7752 for measurement. It has the characteristics which are timesharing measurement, accurate

ss of color, and video display can not only show exercise, clear and fullcolor images, but also show television and puter signals. Although there are some differences between the three, but the most

taining a mand. This is typically coded in the lengths of infrared bursts or in the lengths of gaps between infrared bursts. A long gap or burst is interpreted as a 39。 139。 , a short gap or burst is