EGR 326
The output stage analog circuit model for a TTL device would predict ... a) that the output voltage would be nearly the same as the supply voltage when driven high with a light load (small current draw) b) that the output voltage drops as current is sourced c) that the output voltage increases as current is sinked d) a push-pull circuit can both source current and sink current depending on the logic state e) it is more efficient (less power is dissipated) when sourcing current than when sinking current
b) that the output voltage drops as current is sourced c) that the output voltage increases as current is sinked d) a push-pull circuit can both source current and sink current depending on the logic state
In structured design, ... a) the effort begins with a system architecture b) the effort begins with a requirements analysis and a functional specification document c) hardware design and software design often progress in parallel after each design has been specified d) to verify is to confirm that it meets all requirements, to validate is to confirm it works as designed e) a Systems Requirements Specification (SyRS) defines how to construct the system
b) the effort begins with a requirements analysis and a functional specification document c) hardware design and software design often progress in parallel after each design has been specified
Which of the following are true for the MSP432 I/O ports (circle all that apply)? a) There are 8 I/O ports b) There are 10 I/O ports c) The port registers (e.g., for port 2) are 8 bits wide d) Most port pins have a maximum current rating of 6 mA e) Some port pins are shared with devices on the MCU such as timers
b) there are 10 I/O ports c) the port registers are 8 bits wide d) most port pins have a maximum current rating of 6 mA e) some port pins are shared with devices on the MCU such as timers
The Serial Peripheral Interface ... a) is an asynchronous communication protocol b) typically employs 4 bus lines c) is a full duplex interface (can send and receive at the same time) d) uses a pull-up resistor on the bus lines e) data transmit and receive relies upon simple shift registers
b) typically employs 4 bus lines c) is a full duplex interface (can send and receive at the same time) e) data transmit and receive relies upon simple shift registers
Which of the following is the most popular bit width choice of a microcontroller? a) 8 bits b) 16 bits c) 32 bit d) 64 bits e) none of these
c) 32 bits
When determining a current limit resistor value for the MSP432 I/O port pins driving the RGB LEDs in lab 2, the current should be no more than 10 mA. If the forward bias voltage of the red LED is 1.8V and you tie the common anode of the RGB LED to 5V, the current limit resistor should be (circle best answer.): a) 10 Ω b) 150 Ω c) 320 Ω d) 1000 Ω e) none of these, a different value
c) 320 Ω
Which of the following is NOT an example of classic microcontroller? a) Intel 8051 b) ATMEL AVR c) Intel X86 d) Motorola 68000 e) Microchip PIC
c) Intel X86
When choosing a microcontroller, the most important factor (according to a 2017 survey of design engineers and managers) is: a) Chip cost b) Chip speed c) Software development tools d) Chip power consumption e) Chip I/O or peripherals
c) Software development tools
A touch panel ... a) is commonly made from magnetic materials b) is subject to wear and, therefore, not always a good replacement for a mechanical switch c) is used in restaurants and hospitals because it provides a sealed mechanism that will not harbor germs d) enables large surfaces like table tops to be made very interactive e) made from a resistive material can respond to a gloved hand
c) is used in restaurants and hospitals because it provides a sealed mechanism that will not harbor germs d) enables large surfaces like table tops to be made very interactive e) made from a resistive material can respond to a gloved hand
Describe what is meant by the digital contract in terms of connection digital outputs with digital inputs.
"If you give me a voltage of Vil or lower, I will drive an output voltage of Voh or higher" "If you give me a voltage of Vih or highter, I will drive an output voltage of Vol or lower." If you give me a voltage in between, I cannot guaruntee what output voltage I will drive" This would hold for an inverter.
Given an 8 bit converter, if the reference voltage for a conversion is 3.3V, what is the minimum voltage that can be measured?
(3.3-0)/2^8 = 3.3 / 256 = 0.01289 V or 12.9 mV
Microcontrollers represent what percent of computing devices?
99%
Give an example of a software debounce
A debouncer with a 5 ms delay which moves a bit over every time the same entry (high or low) is received. This goes on for 5 times.
What is a C macro?
A macro is a fragment of code that is given a name. You can use that fragment of code in your program by using the name.
What is a "watch point"?
A watchpoint is set at a data memory location and monitors the changes in that memory. The watchpoint can be set to suspend at a specific value.
Describe and give one advantage and disadvantage of wave drive for a motor
Activates one coil in sequence that attracts the nearest permanent magnet on the rotor. -advantage: simple to control -disadvantage: low torque
Describe and give one advantage and disadvantage of full step drive for a motor
Activates two adjacent coils at a time and the nearest permanent magnet is held halfway between the coils. -advantage: twice the torque of wave drive -disadvantage: twice as much current as wave drive
Describe and give one advantage and disadvantage of half step drive for a motor
Alternates between activating one phase and two phase. -advantage: Provides twice the angle of resolution that wave or full step, slightly more torque than wave drive -disadvantage: more current than wave drive
How are macros used to access memory locations on the MSP432?
By setting a macro equal to the address of a memory location, the address is accessed whenever the macro is called.
Give an example of a hardware debounce
By using an RC circuit, the capacitor must fully charge or discharge to consider a value high or low respectively.
Describe the main advantage of using a PLD such as the PAL22V10 over a microcontroller in an embedded system design. Given an example such as described in class.
Can operate at higher clock rates because it is not decoding instructions, just routing digital signals. Video switcher application where several video feeds need to be handled simultaneously
What is a "break point"?
Causes debugger to suspend execution of a program on the MSP432 at the instruction the break point is set. It enables the debug program to examine registers and memory locations and single step through instructions.
Describe why it usually is not a good idea to connect two digital outputs together.
Creates a contention problem when one output is driving high when the other drives low. It creates a low resistance path between the power supply and ground through the output stage transistors causing too much current.
Describe the main advantages of using a MCU over a programmable logic device. Give an example where this advantage is demonstrated.
Easier to program in a high level language such as C. Easier to provide flexible program through function calls. Security system project where many changes are made incrementally and easily by changing instructions.
How is a bit of data stored on, erased, and read from a memory cell
Erase - SOURCE open, high voltage on gate, draw out floating gate charge Read - SOURCE grounded, apply test voltage, conductivity between drain and source = 1, else 0 Program - SOURCE grounded, high voltage on control gate
Describe the possible signals that could appear on the PLD I/On pin in the figure below
Input signal that can be routed to internal switch matrix when output tristate gate is disabled. Registered output from D flip flop (both normal and inverted) Output from OR gate implementing sum of products of inputs (normal and inverted)
Describe how to simply implement a touch sensor using a standard MCU GPIO pin and a self capaticance technique
MCU sets the pin connected to the electrode as output low to discharge capacitor then, sets electrode pin as an input, and capacitor begins to charge start a counter, look for input to change logic states read counter value and set this as a baseline repeat looking for significant change in counter value if count has increased then the added capacitance of a finger touch can be detected
Describe how a solenoid connects to an MCU
MOSFET is used as a switch to provide a path for current to flow through the solenoid from VDD to ground. A diode connects in parallel with the solenoid to VDD and the drain of the MOSFET to provide a path for current when the MOSFET is off. A resistor connects the gate to the source at 0V to act as a reference. Vin goes to the gate of the MOSFET (port pin)
The 555 timer has been around for decades providing timing signals for many applications. Now that small microcontrollers are cost competitive you don't see them as often in new designs. Describe 3 reasons why this is so.
Many more outputs (up to 5 for the ATtiny device described in lecture) each running independently. No passive external components that may be imprecise and subject to temperature drift. More flexibility, timing of signals can change based on inputs. Can employ unused port pins to implement a communication port.
Sketch a diagram of a standard SPI interface
Master .................. Slave SCK .........................SCK MOSI......................MOSI MISO......................MISO SS.............................SS
Give an example of a macro
P1->DIR designates the memory mapped location for the directional register for port 1
P1OUT |= 0x12;
P1.4 and P1.1 are pull up
List three capabilites provided by the TM4C129 auxiliary MCU on the Launchpad that are useful in developing programs for the MSP432
Provides interface for downloading instructions to the MSP432 target processor from the CCS IDE running on the PC. (provides download interface) Provides debug interface that enables debug programs on the PC control the MSP432 execution Provides serial communication link between PC USB port and the MSP432 serial transmit/recieve lines Provides power to the MSP432 and can be used with an enery trace program to monitor power consumption
Describe two advantages of SPI over I2C
SPI is full duplex, can send and receive at the same time SPI uses a slave select so the slave does not need a built in code to recognize its own address SPI does not have addressing overhead of I2C so it is easier to implement with few slaves SPI can use a faster bit rate than I2C (in general)
How would a program running on the MSP432 detect a key press and identify which one?
Set rows as inputs and use internal pull up resistors, all rows read as 1 Columns brought low one at a time to detect a column of key press. Row input pulled low by a switch in the key. Knowing which row and column are low at the same time gives the key.
WDT_A->CTL = WDT_A_CTL_PW | WDT_A_CTL_HOLD;
Stops watch dog timer
Describe a method for output level shifting. How can you get a 0-3.3 V signal from a device that's operating at 0-5 V levels?
The open collector output can be pulled up to the desired output voltage high level enabling a shift in the signal level from 0-5 to 0-3.3V This was used with a Hall effect sensor output to produce the desired 0-3.3V
Given an 8 bit converter, what two factors affect the resolution of the converter?
The reference voltage and the number of bits
What is the problem with the standard keypad circuit?
There is a possibility of a short circuit if two keys in different columns are pressed at the same time. By setting all columns as inputs initially, there is no output voltage to the pins of the columns until they are one by one switched on or off.
(View Picture)
This step down switching regulator generates a voltage on Cout when current flows from the Vin source through the inductor and is split between the load and Cout. Any current that is not required by the load is used to charge Cout causing the voltage across it to rise. Feedback to the controller element will turn off the pass transistor at the desired output voltage. When the transistor is off, current to the load is supplied by the inductor initially and then when the inductor has discharges, the current comes from the charged Cout. When Cout begins to supply load current, the voltage will drop and this is sensed by the controller that will turn on the pass transistor to now supply current and recharge Cout. This cycle repeats to keep the voltage at the desired regulated level.
Given an 8 bit converter, what is the voltage input if the converter code is 0x0F at a resolution of 12.9 mV?
This would be resolution times code = 12.9 mV * 15 = 0.19335 V
Describe when it is acceptable to connect digital outputs together (and how it is done).
When the output stage is open collector open drain, the outputs can be connected together as in the example of I2C interface. Since an open collector (or drain) device cannot source current, no output contention will occur that can damage the transistors.
The method for analog to digital conversion discussed in lecture is called successive approximation (fill in the blank with a short answer) The converter generates___________________ that is used in the approximation
a digital voltage using a digital to analog converter
The method for analog to digital conversion discussed in lecture is called successive approximation (fill in the blank with a short answer) ______________ is being approximated
a sample of analog voltage
Describe two methods of current protection
a small series resistor connected to each I/O pin to limit the current through each pin, although there will be voltage drop a fuse can prevent too much current but may not respond quickly to overcurrent and can damage sensitive parts active current protection at the main supply by using a PMOS MOSFET that can be turned on to limit flow when overcurrent is sensed
Which of the following is the type of microcontroller used on the TI MSP432 Launchpad? a) ARM Cortex M b) ATMEL AVR c) Intel X86 d) Motorola 68000 e) Microchip PIC
a) ARM Cortex
The serial communication protocol RS232: a) Can be run in full duplex mode (send and receive at the same time) b) Has at least 9 defined signals, but, can be run in half duplex mode with only 1 signal and ground c) Uses voltages of < -3V to represent a logic 1 and > 3V to represent a logic 0 d) Requires both the sending and receiving devices to know the bit rate and number of data bits e) Determines start of transmission of a data byte with a downward edge transition on the TD line
a) Can be run in full duplex mode (send and receive at the same time) b) Has at least 9 defined signals, but, can be run in half duplex mode with only 1 signal and ground c) Uses voltages of < -3V to represent a logic 1 and > 3V to represent a logic 0 d) Requires both the sending and receiving devices to know the bit rate and number of data bits e) Determines start of transmission of a data byte with a downward edge transition on the TD line
Which of the following are true for I2C implementation (circle all that are true)? a) Each device on the I2C bus must have a unique address b) Signaling on the bus is done with a simple transistor and resistor pair c) The bus is pulled low by the resistor d) The bus is pulled high by the resistor e) The bus is pulled high by the transistor
a) Each device on the I2C bus must have a unique address b) Signaling on the bus is done with a simple transistor and resistor pair d) The bus is pulled high by the resistor
A pulse width modulated (PWM) signal: a) Is defined by its duty cycle. b) Changes the power delivered to a load by changing the pulse height. c) Changes the power delivered to a load by changing the pulse width with respect to its period. d) Can be created easily using a 16 bit Timer A. e) Can be created using program instructions to connect Timer A output directly to a MSP432 I/O pin
a) Is defined by its duty cycle. c) Changes the power delivered to a load by changing the pulse width with respect to its period. d) Can be created easily using a 16 bit Timer A. e) Can be created using program instructions to connect Timer A output directly to a MSP432 I/O pin
Which of the following are true for using the printf() function in debug mode in CCS ? a) It will output to the console window unless different low level routines are written. b) It sets a breakpoint in your code and then sends the formatted data to the console window. c) It is the most time efficient way to send characters to a terminal screen. d) You need to include the stdint.h file in your program so the compiler can find the routines. e) It can be a useful debugging tool as long as there are no time critical elements in your program
a) It will output to the console window unless different low level routines are written. b) It sets a breakpoint in your code and then sends the formatted data to the console window. e) It can be a useful debugging tool as long as there are no time critical elements in your program
Which of the following are true for the clock system in the MSP432? a) There are 5 possible clock signals from 7 different sources. b) There are 2 clock sources that can be external crystals connected to MSP432 I/O pins. c) The default clock is the external 48 MHz clock d) The internal Digitally Controlled Oscillator (DCO) clock source is the most accurate. e) One of the clock sources can run as slow as 10 KHz
a) There are 5 possible clock signals from 7 different sources. b) There are 2 clock sources that can be external crystals connected to MSP432 I/O pins e) One of the clock sources can run as slow as 10 KHz
Circle all of the MSP432 timer types: a) Timer A b) Timer B c) Timer 32 d) SysTick e) WDT
a) Timer A c) Timer 32 d) SysTick e) WDT
For the interrupt control on the MSP432 (circle all answers that are true): a) Your program must enable three things, the module sources, the module, and the master interrupt b) A bit is set in the device register when it requests an interrupt c) An interrupt service routine (ISR) is used to respond to a device interrupt request d) It is usually good practice to just set a flag (global variable) within the ISR or execute as few instructions as possible e) The MSP432 can handle only one interrupt at a time and the ISR must complete before another is recognized
a) Your program must enable three things, the module sources, the module, and the master interrupt b) A bit is set in the device register when it requests an interrupt c) An interrupt service routine (ISR) is used to respond to a device interrupt request d) It is usually good practice to just set a flag (global variable) within the ISR or execute as few instructions as possible
When interfacing the MSP432 with an LCD ... a) all 8 eUSCI modules on the MSP432 are available for SPI b) the MOSI (SIMO) line is not used c) the MISO (SOMI) line is not used d) the STE line is used for slave select e) an additional line is needed to switch between command and data modes
a) all 8 eUSCI modules on the MSP432 are available for SPI c) the MISO (SOMI) line is not used d) the STE line is used for slave select e) an additional line is needed to switch between command and data modes
A DC motor ... a) can be a "brushed" type that uses a commutator to reverse current flow through a coil on the rotor b) can be a "brushless" type that typically has current that flows through stationary coils c) can be a brushed motor that relies on permanent magnets in the rotor to achieve motion d) can be a brushless motor that relies on permanent magnets in the rotor to achieve motion e) of a brushed type will change speed depending on the applied voltage
a) can be a "brushed" type that uses a commutator to reverse current flow through a coil on the rotor b) can be a "brushless" type that typically has current that flows through stationary coils d) can be a brushless motor that relies on permanent magnets in the rotor to achieve motion e) of a brushed type will change speed depending on the applied voltage
Crosstalk ... a) can be due to mutual capacitance or mutual inductance b) can be interference caused by a steady current in a conductor with nearby stationary conductors c) can be cancelled by running a return conductor in a parallel path to the signal conductor d) can be worse the larger the distance between conductors e) between analog and digital circuits can be a problem when they share a common ground plane
a) can be due to mutual capacitance or mutual inductance c) can be cancelled by running a return conductor in a parallel path to the signal conductor e) between analog and digital circuits can be a problem when they share a common ground plane
A switching voltage regulator ... a) can produce a regulated voltage that is higher than the input voltage b) can create an efficiency measure that is greater than 100% c) regulates voltage by changing the duty cycle of a transistor that is turned on and off d) is generally quieter (in terms of EMF) than a linear regulator e) uses the energy storage capability of inductors and capacitors
a) can produce a regulated voltage that is higher than the input voltage c) regulates voltage by changing the duty cycle of a transistor that is turned on and off e) uses the energy storage capability of inductors and capacitors
A linear voltage regulator ... a) could be as simple as a zener diode with current limiting resistor b) typically uses a transistor to pass current to a load or shunt current from a load c) is measured in efficiency by the ratio of power in over power out d) "drop out" is responsible for reducing regulator efficiency e) is available in a low drop out form that improves regulator efficiency
a) could be as simple as a zener diode with current limiting resistor b) typically uses a transistor to pass current to a load or shunt current from a load d) "drop out" is responsible for reducing regulator efficiency e) is available in a low drop out form that improves regulator efficiency
Which of the following are true for the SysTick timer (circle all that apply)? a) It counts down to 0 b) It counts up to a maximum value c) It counts CPU bus clock cycles d) It has a 32 bit sized register to keep track e) It sets a bit when the time has expired
a) counts down to 0 c) counts CPU bus clock cycles e) it sets a bit when the time has expired
A programmable logic device ... a) is an option for a control device in an embedded system design. b) in its simplest form is about the same price as a low end microcontroller. c) is often used to replace dedicated logic devices such as decoders, shift registers, counters, and bus interfaces. d) can provide combinational or sequential logic circuits, but, not both. e) has internal fuses that must be melted to open circuit connections with the aid of a programmer device.
a) is an option for a control device in an embedded system design. b) in its simplest form is about the same price as a low end microcontroller. c) is often used to replace dedicated logic devices such as decoders, shift registers, counters, and bus interfaces.
The solenoid operates with the following principles. It ... a) is dependent on a magnetic field that develops a magnetic orientation on a soft metal plunger b) can reverse the direction of the plunger by reversing the current through the coil c) develops a force that is proportional to the square of the number of turns of wire in the coil times the current flow d) develops less force when the stroke is limited to a few mm e) can be driven by a higher voltage than the coil is designed for if the duty cycle is long
a) is dependent on a magnetic field that develops a magnetic orientation on a soft metal plunger c) develops a force that is proportional to the square of the number of turns of wire in the coil times the current flow
The MSP432 Power Supply System (PSS) ... a) monitors the input voltage to the device and will create a power-on reset if the power drops below a minimum. b) monitors the input voltage to the core logic and will create a power-on reset if the power drops below a minimum. c) generates a supply voltage for the core logic. d) enables your software to read a register to determine if there has been a power-on reset condition. e) provides "brown-out" protection for the main purpose of lowering the energy consumption of the MCU.
a) monitors the input voltage to the device and will create a power-on reset if the power drops below a minimum. b) monitors the input voltage to the core logic and will create a power-on reset if the power drops below a minimum. c) generates a supply voltage for the core logic. d) enables your software to read a register to determine if there has been a power-on reset condition.
The MSP432 watchdog timer ... a) runs independent of the rest of the MCU and can cause a power-on reset when it times out. b) is disabled by default. c) must be reset periodically by your software when it's used. d) watches a memory location assigned as a variable by your program. e) runs off the MCLK.
a) runs independent of the rest of the MCU and can cause a power-on reset when it times out. c) must be reset periodically by your software when it's used.
The MSP432 has several features designed to minimize power consumption including ... a) several clock choices to minimize the clock rate for the various internal peripheral devices. b) a switching voltage regulator that requires an external inductor. c) sleep modes that cause the system to halt several clocks to save power. d) the ability to wake up from a sleep mode by timer interrupt or GPIO signal change event. e) the ability to run on a single AAA battery at 1.25V
a) several clock choices to minimize the clock rate for the various internal peripheral devices. b) a switching voltage regulator that requires an external inductor. c) sleep modes that cause the system to halt several clocks to save power. d) the ability to wake up from a sleep mode by timer interrupt or GPIO signal change event.
The input stage analog circuit model for a TTL device would predict ... a) that leakage current when the input is externally pulled to logic low can be as large as 200 microamps b) that leakage current when the input is externally pulled to logic high can create a problem when the pullup resistance is too large c) that the logic switching threshold is lower than for CMOS devices d) that VIL is the maximum voltage considered as logic low e) that VOH is lower than VIH for CMOS leading to a problem when TTL is driving CMOS devices
a) that leakage current when the input is externally pulled to logic low can be as large as 200 microamps b) that leakage current when the input is externally pulled to logic high can create a problem when the pullup resistance is too large c) that the logic switching threshold is lower than for CMOS devices d) that VIL is the maximum voltage considered as logic low e) that VOH is lower than VIH for CMOS leading to a problem when TTL is driving CMOS devices
The input stage analog circuit model for a CMOS device would predict ... a) that leakage current when the input is externally pulled to logic low is usually around 1 microamp b) that the rise times and fall times of the edges of a rapidly changing signal may be affected by effective capacitance c) that a floating input will settle at a voltage close to the switching threshold d) that a floating input will result in much lower power dissipation than if pulled high or low e) that the noise margin for CMOS is less than for TTL
a) that leakage current when the input is externally pulled to logic low is usually around 1 microamp b) that the rise times and fall times of the edges of a rapidly changing signal may be affected by effective capacitance c) that a floating input will settle at a voltage close to the switching threshold
The output stage analog circuit model of a CMOS device would predict ... a) that the output voltage would be nearly the same as the supply voltage when driven high with a light load b) that the output voltage would be nearly 0V when driven low with a light load c) that an open drain configuration can drive high and source current d) that open drain outputs from two devices can form a NOR circuit without an additional gate e) that a tri-state output state has a high impedance that helps isolate it from other circuit elements
a) that the output voltage would be nearly the same as the supply voltage when driven high with a light load b) that the output voltage would be nearly 0V when driven low with a light load d) that open drain outputs from two devices can form a NOR circuit without an additional gate e) that a tri-state output state has a high impedance that helps isolate it from other circuit elements
For the eUSCI module of the MSP432 in SPI mode ... a) the clock is always generated by the master device b) a flag bit in a register indicates when a transfer is complete c) it transfers data a byte at a time d) the data transfer rate is derived from the chosen clock e) the transfer rate can operate at the full 48 MHz clock
a) the clock is always generated by the master device b) a flag bit in a register indicates when a transfer is complete c) it transfers data a byte at a time d) the data transfer rate is derived from the chosen clock
The RGB LED in your kit is a common anode configuration. This means in order to get an LED to light: a) The common should be tied to Vcc and each of the other pins should be brought low through a R b) The common should be tied to Gnd and each of the other pins should be brought low through a R c) The common should be tied to Vcc and each of the other pins should be brought high through a R d) The common should be tied to Gnd and each of the other pins should be brought high through a R e) It does not matter if the common pin is tied to Vcc or Gnd in the case of the lab 2 exercise
a) the common should be tied to Vcc and each of the other pins should be brought low through a resistor
In a voltage regulator, ... a) the transistor used in a switching regulator is always all the way on or all the way off b) the transistor used in a linear regulator is always all the way on or all the way off c) the output capacitor supplies current to the load during part of the switching regulation cycle d) the capacitors and inductors need to be specified for carrying high currents in a switching regulator e) for a step up switching converter, a longer transistor on-time enables higher current through an inductor that leads to a higher voltage on an output capacitor when the transistor is turned off
a) the transistor used in a switching regulator is always all the way on or all the way off c) the output capacitor supplies current to the load during part of the switching regulation cycle d) the capacitors and inductors need to be specified for carrying high currents in a switching regulator e) for a step up switching converter, a longer transistor on-time enables higher current through an inductor that leads to a higher voltage on an output capacitor when the transistor is turned off
The following could create an overcurrent problem ... a) touching a wire to ground that is connected to an I/O port pin configured as an output b) touching a wire to ground that is connected to an I/O port pin configured as an input c) connecting an output pin driving high to an input pin d) connecting an output pin driving high to an output pin driving low e) connecting a large number of current limited LEDs
a) touching a wire to ground that is connected to an I/O port pin configured as an output d) connecting an output pin driving high to an output pin driving low e) connecting a large number of current limited LEDs
If we assume the default clock rate for the MSP432 on the Launchpad board, what would be loaded into the SysTick timer RELOAD VALUE register for a 1 ms time interval (circle best answer only)? a) 1000 b) 3000 c) 1000000 d) 3000000 e) None of the above
b) 3000
The most used programming language for embedded system development (according to a 2017 survey of design engineers and managers) is: a) Java b) C c) C++ d) Assembly e) Python
b) C
High speed parallel interfaces are not used commonly for PC interfaces because: a) Parallel communication is inherently slower than serial communication b) Cross talk between bit lines can corrupt a message sent over any appreciable distance c) Parallel connectors take up more space and require more wires d) When traveling over a distance, the timing of arrival of the various lines gets skewed e) There was no advantage in sending all bits of a character at the same time
b) Cross talk between bit lines can corrupt a message sent over any appreciable distance c) Parallel connectors take up more space and require more wires d) When traveling over a distance, the timing of arrival of the various lines gets skewed
Which of the following are true for the MSP432 ADC (circle all that are true)? a) It is a 12 bit converter b) It is a 14 bit converter c) It can convert multiple analog inputs simultaneously d) It can convert multiple analog inputs sequentially e) It can use adjacent channels to convert a differential signal
b) It is a 14 bit converter d) It can convert multiple analog inputs sequentially e) It can use adjacent channels to convert a differential signal
When deciding on a regulator, ... a) linear series regulators are more efficient than a switching regulator b) LDO regulators are chosen to reduce the "dropout" of a regulator circuit c) switching regulators don't cost much more than a 7805 linear regulator d) switching regulators are a better choice than linear regulators for battery operated circuits e) if you had a noise sensitive circuit, you would use a linear regulator to power it
b) LDO regulators are chosen to reduce the "dropout" of a regulator circuit d) switching regulators are a better choice than linear regulators for battery operated circuits e) if you had a noise sensitive circuit, you would use a linear regulator to power it
When considering memory types in MCUs ... a) EEPROM is used for read only purposes and stores driver library routines b) ROM is used for read only purposes and stores driver library routines c) flash memory is a type of EEPROM d) program memory is flash e) your programmed instructions are stored in RAM f) volatile memory requires continual application of electrical power to store information g) flash is a type of volatile memory h) to program a flash memory cell requires a much higher voltage than to read it i) to program EEPROM takes much longer than to read it j) an erased flash memory cell reads as a logic 1 k) EEPROM memory can be addressed in bytes while flash needs to be addressed in Kbytes l) flash memory costs more than EEPROM m) static RAM (SRAM) requires a constant refresh n) SRAM has a larger footprint and is more expensive than dynamic RAM (DRAM) o) the types of memory found in the MSP432 are ROM, flash, and SRAM
b) ROM is used for read only purposes and stores driver library routines c) flash memory is a type of EEPROM d) program memory is flash f) volatile memory requires continual application of electrical power to store information h) to program a flash memory cell requires a much higher voltage than to read it i) to program EEPROM takes much longer than to read it j) an erased flash memory cell reads as a logic 1 k) EEPROM memory can be addressed in bytes while flash needs to be addressed in Kbytes n) SRAM has a larger footprint and is more expensive than dynamic RAM (DRAM) o) the types of memory found in the MSP432 are ROM, flash, and SRAM
Which of the following are true for the I2C communication protocol (circle all that are true)? a) It is an asynchronous communication protocol b) There can be many devices on the same bus c) The bus consists of 2 wires (plus a ground reference) d) The bus consists of 4 wires e) It is a master-slave protocol with the master device in control
b) There can be many devices on the same bus c) The bus consists of 2 wires (plus a ground reference) e) It is a master-slave protocol with the master device in control
When interfacing a solenoid with an MCU, ... a) the current required to activate it can be supplied by the MCU I/O pin b) a device that can switch high current through the coil is necessary to activate it c) a "fly-back" diode should be employed if a transistor is used for switching current flow d) a program can be used to control water flow e) a series of them can be used to accelerate a projectile
b) a device that can switch high current through the coil is necessary to activate it c) a "fly-back" diode should be employed if a transistor is used for switching current flow d) a program can be used to control water flow e) a series of them can be used to accelerate a projectile
A stepper motor ... a) can be a DC brushed type motor of a specific design b) can be a DC brushless type motor using a specific design c) has continuous motion and cannot be held in one position d) aligns permanent magnet poles on the rotor with an activated coil generating a magnetic field e) will change speed depending on the applied voltage
b) can be a DC brushless type motor using a specific design d) aligns permanent magnet poles on the rotor with an activated coil generating a magnetic field
Touch panels that are capacitive, ... a) need a certain pressure to activate them b) can be used in applications requiring two finger touch c) can be based on mutual capacitance where a finger interferes with an electrostatic field and reduces the effective capacitance causing a change in capacitance to be detected d) can be based on self capacitance where a finger adds to the effective capacitance causing a change in capacitance to be detected e) typically
b) can be used in applications requiring two finger touch c) can be based on mutual capacitance where a finger interferes with an electrostatic field and reduces the effective capacitance causing a change in capacitance to be detected d) can be based on self capacitance where a finger adds to the effective capacitance causing a
In addition to crosstalk, other signal integrity issues ... a) include ground bounce due to an intermittent ground connection from faulty wiring b) include effects of rapidly changing signals causing voltage drops across wire connections c) include a difference between system ground and localized ground inside an integrated circuit d) include a difference between system voltage supply and localized supply voltage inside an IC e) can sometimes be solved by using decoupling capacitors
b) include effects of rapidly changing signals causing voltage drops across wire connections c) include a difference between system ground and localized ground inside an integrated circuit d) include a difference between system voltage supply and localized supply voltage inside an IC e) can sometimes be solved by using decoupling capacitors
How were keys read from the columns/ rows in a keypad?
columns initially set as inputs column 1 set as output column 1 driven low delay rows read columns set as inputs column 2 set as output... ect
The objective of lab 4 was to (circle best ans.): a) to generate a PWM signal b) to read a voltage with an ADC c) to simulate backlight control of an LCD d) a, b, and c e) none of these
d) a, b, and c
One of the hardware debounce techniques described in the Ganssle article (circle best answer only): a) Required the use of resistors and a capacitor to create an RC time constant b) Required an inverter gate with a Schmidt trigger input used as a voltage comparator c) Required a double throw switch d) Required an S-R flip e) All of the above
e) all of the above
P1REN |= 0x12; .. means
enable pull resistors on P1.4 and P1.1
Describe two advantages of a switching regulator over a linear regulator
has better efficiency can provide higher voltage on the output than is input
What are two methods to reduce crosstalk in embedded systems
introduce a ground plane or grounded trace between signal traces keep signal lines far apart from one another and keep them as short as possible
Describe a method to reduce ground bounce and one to reduce supply bounce
keep ground leads as short as possible to reduce inductance and ground them to a ground plane immediately beneath the ground pin connection if possible use coupling capacitors to act as a reservoir of charge to keep the voltage from sagging when rapid draws of current from the supply would create a voltage drop across inductance in the supply lead
Describe two advantages of linear regulator over a switching regulator
less EMF because it is not switching high currents and creating electromagnetic radiation as a result less expensive
P1DIR &= ~ 0x12; ... means
make P1.4 and P1.1 inputs
Describe typical I2C communication
master pulls line low (sending transmit signal) sends out address of desired slave sends write/read slave sends a bit to acknowledge master/slave sends a byte of data slave/master acknowledges master finishes trasmission by sending reapeated start or stop bit
Describe two methods of voltage protection
placing a current limited zener diode between an input and ground limits input voltage on the pin to the zener diode reverse bias voltage monitoring the power supply voltage with a resistor divider circuit connected to the inverting terminal of an op amp with a voltage reference on the non inverting terminal placing a Schottky diode in series with the power supply to protect against reverse voltage
Describe two advatages of I2C over SPI
requires only 2 lines for bidirectional communiciation, clock, and data - SPI requires a line for each slave provides acknowledgement for each byte of data sent easier to have multipe masters on the same bus
The method for analog to digital conversion discussed in lecture is called successive approximation (fill in the blank with a short answer) The input must first be ______________________
sampled at the appropriate frequency and the voltage held
P1SEL0 &= ~ 0x12; P1SEL1 &= ~ 0x12; .... means
set P1SEL0 and P1SEL1 registers to configure P1.4 and P1.1 as GPIO
addr_pointer = CALIBRATION_START + 4 //means
set a pointer to the address in the flash memory address space where you want to store data, skipping 4 bytes containing the Boot Override Mailbox instructions
P1->DIR |= BIT0
sets GPIO port 1 pin 0 to output
The method for analog to digital conversion discussed in lecture is called successive approximation (fill in the blank with a short answer) The successive approximation register (SAR) contains _____________________
the digital code representing the closest digital voltage to the analog sample
The method for analog to digital conversion discussed in lecture is called successive approximation (fill in the blank with a short answer) ______________________ flag signals the microcontroller that the process is complete
the end of conversion flag
