AT89S51 Microcontroller

The Atmel AT89S52 Microcontroller or commonly known as AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of in-system programmable Flash memory. The device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.

W78E052DDG is a successive microcontroller unit that is fully compatible with the widely popular 8052 despite having an 8051 core. It is an 8-bit architecture-based microcontroller unit that has 8 kilobytes of Flash. It has 256 bytes of RAM, 4 8-bit bi-directional I/O ports, specified as P0, P1, P2, P3, and 4-bit I/O port P4. Three 16-bit timer/counters, a hardware watchdog timer, and a serial port make this microcontroller easy to integrate with multiple applications. The specialty of this microcontroller unit is the optional 12T or 6T mode. In 12T mode, it uses 12 clocks per machine cycle where the speed of the processor goes up to 40 MHz at 5V operating voltage. At the same time, if 6T Mode is selected, 6 clocks per machine cycle operation make the controller speed up to 20 MHz at 5V operating voltage. It supports 2.4V to 5.5V operation, which makes it suitable for 3.3V to 5V logic level operations.

The AT89C55 is a 8-bit low-power High-performance CMOS Microcontroller with 20kB of flash programmable read only memory and 256 bytes of RAM. The device is manufactured using Atmel's high-density non-volatile memory technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pinout. The on-chip Flash allows the program memory to be user programmed by a conventional non-volatile memory programmer. By combining a versatile 8-bit CPU with flash on a monolithic chip, the Atmel AT89C55 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. The AT89C55 provides the following standard features 20kB of Flash, 256 bytes of RAM, 32 I/O lines, three 16-bit timer/counters, a six-vector, two-level interrupt architecture, a full-duplex serial port, on-chip oscillator and clock circuitry.

The P89V51RD2 is an 80C51 microcontroller by NXP (Phillips) with 64 kB Flash and 1024 bytes of data RAM. A key feature of the P89V51RD2 is its X2 mode option. The design engineer can choose to run the application with the conventional 80C51 clock rate (12 clocks per machine cycle) or select the X2 mode (6 clocks per machine cycle) to achieve twice the throughput at the same clock frequency. Another way to benefit from this feature is to keep the same performance by reducing the clock frequency by half, thus dramatically reducing the EMI. The Flash program memory supports both parallel programming and in serial In-System Programming (ISP). Parallel programming mode offers gang-programming at high speed, reducing programming costs and time to market. ISP allows a device to be reprogrammed in the end product under software control. The capability to field/update the application firmware makes a wide range of applications possible. The P89V51RD2 is also In-Application Programmable (IAP), allowing the Flash program memory to be reconfigured even while the application is running.