Week 7 :Research The Micro-controller

                The 8051 is an original member of the 8051 family. There are two other members in the 8051 family of microcontrollers. They are 8052 and 8031. All the three microcontrollers will have the same internal architecture, but they differ in the following aspects.

Ø  8031 has 128 bytes of RAM, two timers and 6 interrupts.

Ø  89S51 has 4KB ROM, 128 bytes of RAM, two timers and 6 interrupts.

Ø  89S52 has 8KB ROM, 128 bytes of RAM, three timers and 8 interrupts.

Of the three microcontrollers, 89S51 is the most preferable. Microcontroller supports both serial and parallel communication.

             In the concerned project 89S52 microcontroller is used. Here microcontroller used is AT89S52, which is manufactured by ATMEL laboratories.

           The AT89S52 provides the following standard features: 8Kbytes of Flash, 256 bytes of RAM, 32 I/O lines, three 16-bit timer/counters, six-vector two-level interrupt architecture, a full duplex serial port, on-chip 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 Power down Mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next hardware reset.

           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.

By combining a versatile 8-bit CPU with Flash on a monolithic chip, the AT89C52 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications.