DS80C390-QCR+

The DS80C390-QCR+ is a member of the 80C390 family of microcontrollers from Dallas Semiconductor (now integrated into Maxim Integrated, in the Embedded Processing Solutions group). It is a CMOS 8-bit microcontroller optimized for embedded control applications, featuring on-chip peripherals that allow connection to a variety of common external input/output (I/O) devices without external logic or glue chips, so it provides a cost-effective option for embedded control developers dealing with space and power limitations.

The DS80C390-QCR+ incorporates a 5 V, 8-bit version of the Intel Architecture-compatible 80186 CPU, as well as various kinds of interactive I/O integrated circuits. In addition, its small form factor, low power consumption, and wide range of features make this microcontroller suitable for a variety of embedded control applications.

The DS80C390-QCR+ includes the following features to support embedded control applications:

• Integrated peripherals: These allow the DS80C390-QCR+ to interface directly with external inputs and outputs with minimal additional hardware. The onboard peripherals include two 16-bit timer/counters, high-current output I/O ports, a serial port, an analog-to-digital converter, an interrupt controller, an SPI interface, and a universal synchronous/asynchronous receiver/transmitter. These enable designers to implement a wide variety of embedded control applications with minimum hardware.
• Small size and low power consumption: The DS80C390-QCR+ is available in a 28-pin package making it ideal for space-constrained applications, while its low power consumption makes it suitable for battery-powered systems.
• On-chip debug capability: The DS80C390-QCR+ includes features to facilitate on-chip debugging, such as breakpoints, trace buffer, single-step and real-time execution, as well as watchpoint and breakpoint capability. These features make it easier to develop and debug applications for the DS80C390-QCR+.
• Software compatibility: The DS80C390-QCR+ is compatible with C and assembly language programming schemes and can be used with a variety of development tools, including the Dallas Semiconductor Embedded Systems System Development Kit, Code Composer Studio, and Microsoft Visual Studio.

The DS80C390-QCR+ is suitable for a variety of applications, such as embedded control of motors, pumps, valves, and other industrial equipment; building and home automation; personal digital assistants; and set-top box and automotive control. The device can also be used as a controller for medical, laboratory, and test equipment.

In terms of its working principle, the DS80C390-QCR+ is fundamentally just a microprocessor. Like regular microprocessors, the DS80C390-QCR+ has an instruction set, an ALU that performs arithmetic and logical operations, and a set of registers to store data. Its main difference is the addition of I/O peripherals that are integrated on-chip, making it well-suited for embedded control applications.

When the DS80C390-QCR+ is powered up, the CPU starts at a predefined address and executes a program stored in the device\'s ROM. The program can be written in either assembly language or a high-level language such as C. The CPU fetches instructions one by one, interprets them, and executes them. The I/O peripherals are used to control external components and devices, such as relays, motors, and sensors, or to transfer data from the device to other devices. The on-chip timers can be used to generate periodic events, or the device can use an external trigger such as a signal from a sensor, to initiate an event.

To conclude, the DS80C390-QCR+ is an 8-bit microcontroller from Maxim Integrated\'s Embedded Processing Solutions group, optimized for embedded control applications. It offers an impressive range of features, including integrated I/O peripherals, small size and low power consumption, and on-chip debug capability. It is suitable for a variety of applications, ranging from motor and pump control to home automation and PDA control. Its working principle is the same as that of any microprocessor: execute a program stored in the device\'s ROM and use the I/O peripherals to interact with external devices.