Embedded Systems

Use this for “An 8-bit DAC with a 5 V reference gets the code 200. What voltage comes out?”

Use this for “A 3.3 V pin drives an LED with a 2 V drop at 10 mA. What resistor goes in series?”

Use this for “A 5 V signal reaches a 3.3 V pin through 2.2 kΩ over 3.3 kΩ. What voltage does the pin see?”

Use this for “An 8-bit register holds 0x41. Set bit 3, then clear bit 6. What does it hold?”

Use this for “A 16 MHz timer with prescaler 8 counts to TOP = 1999 and compares at 500. Find the PWM frequency, duty and average voltage at 5 V.”

Use this for “How long can a 16-bit timer at 16 MHz run with prescaler 1024 before it overflows?”

Use this for “An interrupt fires at 10 kHz and its ISR takes 20 μs. What share of the CPU does it use?”

Use this for “A timer matches its compare value. Put in order what the CPU does until the main program resumes.”

Use this for “A 16 MHz microcontroller sets its UART to 115 200 baud. What goes in UBRR, and how far off is the baud rate?”

Use this for “An SPI bus clocks at 8 MHz. How many bytes a second can it move, and how long does a 16-bit transfer take?”

Use this for “How long does a 400 kHz I²C write of 2 data bytes take, address byte included?”

Use this for “A bus has two shared wires, pull-up resistors and a 7-bit address for each device. Is it UART, SPI or I²C?”

Use this for “Find the worst-case response time of task 3 in (1, 4), (2, 8), (3, 12) ms.”

Use this for “Tasks (C, T) = (2, 5), (2, 7), (1, 10) ms: can EDF schedule them? Can rate-monotonic promise to?”