Question

simple MSP430 Q&A QUESTION

run on Code Composer Studio flashing led

1. In this lab, we used a delay loop to create a small delay; what is its effect on the battery life if the device is battery operated? Is it a good way of generating delays?

2. The MSP430 CPU runs on a clock that can be slowed down or sped up; what happens to the delay generated by the delay loop if the clock driving the CPU speeds up or slows down?

3. How does the code run in the debug mode? Is the microcontroller running as an independent computer?

4. How does the code run in the normal mode? Is the microcontroller running as an independent computer?

5. In which mode does the reset button work?

6. What is the data type uint16 t ? What about int16 t ? Are these standard C syntax?

Answer 1

1.The MSP430 is the lowest-power microprocessor available in the market. Its inherently low-power operation is ideal for battery-powered applications where frequent battery replacement is undesirable.In an attempt to prolong battery life, software engineers go to great lengths to optimize code, minimize memory accesses, etc. Hardware engineers focus on ways to shut down unused circuitry, ensure that all quiescent currents and leakage paths are minimized, and maximize powersupply efficiency.Many MSP430 designs do not need an input power supply because the MSP430 device family accepts extremely wide variations in input voltage. For example, the MSP430FG4618 operates with an input voltage of between 1.8 V and 3.6 V. Because of this wide input range, many MSP430 designs operate directly from a battery without additional power conversion.So.if the device is battery generated,there will be efficient delays.

2.A microcontroller and its peripherals are just sequential logic circuits. Remember that sequential logic circuits need a clock signal. Before a CPU can operate, it must have power, a clock signal, and ground.The edges of the clock are responsible for driving all of the logic circuits in the CPU. All CPU instructions take a certain number of clock cycles to execute.The clock provides the system's time reference. All of the timers on the MSP430 count clock signals to measure elapsed time. In this way, the system's clock forms the base for the whole system.Microprocessors usually allow you to configure the clocks used by the system. On the MSP430, this tasks is handled by the Unified Clock System (UCS).the MSP430 has a variety of configurable clock sources, which can be used to drive a number of clock signals inside the chip. These various clock signals are responsible for driving the CPU core and all of the peripherals.

3.We can try to retrieve the values from the ADC on my MSP430F5529 and send them to my computer over USB, we can start small. All we have right now something that retrieves the ADC value and stores it in ADCResults, if the read value is over half of Vcc then an LED turns on.We have pin 6.0 hooked up to a force sensor so we can see it turn off and on when I put my finger down on it or release it.The program works perfectly when we run it in debug mode .

4.The interrupt normal code execution-the normal code runs in the foreground. Normal code(eg.main()function) runs in the background.Interrupts can be enabled and disabled globally,individually on a per-peripheral basis and Non-Maskable Interrupt.

5.If we are developing an application based on a msp430f169. A reset button is a part of the design, but nothing happens when the reset button is operated, the program just keeps on running. The reset button is connected to pin 58, RST/NMI.One of the first lines in the program is WDTCTL = WDTPW + WDTHOLD; bit 5 of the wdtctl register controls the function of the pin, and setting this to zero should leave the pin in reset mode.So,the reset works in normal mode as it is causing some problems in debug mode.

6.The unsigned integer numbers may be expressed in either decimal or hexadecimal notation. A number in hexadecimal notation begins with the prefix 0x. The literals can be used within expressions wherever an uint8, uint16 or uint32 operand is expected.we would have to use another type, for example an unsigned short or an uint16t equal to 2 bytes or 16 bits.And Yes they are Syntax of C.