Embedded Systems / Quiz
Problem 1Give one sentence/phrase that describes the purpose of the diodes shown in the simplified equivalent diagram of an I/O port on an AVR ATmega88P controller. (10 points)
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Problem 2Complete the following glossary of terminology encountered in embedded systems.
Problem3 Give one sentence/phrase that describes the purpose of the diodes shown in the simplified equivalent diagram of an I/O port on an AVR ATmega88P controller. (10 points)
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Problem 4 Show a code snippet to copy a byte from SRAM memory address 0x100 to r1 on an SAMSUNG 2410. (10 points)
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Problem 5Assume the contents of the register R18 is 0xB2. What will the contents be after the instruction NEG R18?(10 points)
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Problem 6The following signal is obtained from an RS232 line.
a) What is the baud rate of the signal? Baud rate= __________Baud.
b) What are the transmission parameters? ___________ Bits,__________ parity.
c) What is the transmitted character?
in bin form: 0b___ ___ ___ ___ ___ ___ ___ ___ in hex format : 0x ___ ___ d) If Fosc = 460KHz, what shall be the settings for SPBRG register and BRGH flag for a 2400 Baud transmission?
BRGH= __________ 0 or 1 ; SPBRG =_____________(in decimal) 2 or 11
(10 points)
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Problem 7A programmer uses the 16-bit timer TIMER1 on the ATmega88PA to generate square 5 kHz waves. She uses the timer overflow ISR that toggles an output pin and then reloads the counter register(s). The 8-MHz clock is not prescaled. What is the required reload count?
(10 points)
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Problem 8Assume the contents of register R18 is 0xB2 and the contents of register R19 is 0x33. What are the contents of registers R18 and R19 after the instruction ADD R18,R19 ? (10 points) Answer:
Problem 9
Write the C-code to manipulate the ports as described in the following table, using the symbols PORTA, TRISA, and LATA only (i.e., PORTA=0x01 etc.)
a) In PORTA, configure the bits 0...5 as input, and bits 6, 7 as output. ____________________
b) Make PORTA, bit-6 high, without modifying the other bits.____________________
c) Read PORTA bits into an 8-bit variable Y _____________________
d) Write an if-then clause to test bit-3 of PORTA. You have to set both output-bits to high if bit-3 is low.
__________________________
__________________________
Problem 10Provide a code snippet to initialize the 16-bit counter to TIMER1 register TCNT1 to 0x01FF. (10 points)
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Problem 11 The following circuit works on battery and supply voltage Vdd is unknown.
a) After an ADC with the settings ADCON0=110111012, and ADCON1=000001002 , ADRESH
contains 150 and ADRESL contains 0. If v3 is exactly 2 volts, what is the voltage value of the supply voltage Vdd.Vdd = _________volts.
b) After an ADC with the settings ADCON0=110001012, and ADCON1=100011112 , what will be the contents of ADRESH and ADRESL if v0=1.4V, v1=1.8V, v2=1.0V and v3=2.0V? ADRESH=__________(dec) ; ADRESL= ___________ (dec).。