Embedded Systems & Programming Flashcards

Which serial communication protocol uses separate MOSI, MISO, SCLK, and chip-select lines?

Answer: SPI

SPI (Serial Peripheral Interface) uses four dedicated lines: MOSI, MISO, SCLK, and one CS line per slave device.

In I2C communication, what is the function of pull-up resistors on the SDA and SCL lines?

Answer: They pull the open-drain lines high when no device is driving them low

I2C uses open-drain outputs, so pull-up resistors are required to return the bus to a logic-high idle state when no device is asserting it low.

What does 'baud rate' specify in a UART configuration?

Answer: The number of symbol transitions per second on the line

Baud rate is the number of signaling events (symbols) per second; in UART with binary signaling, it equals the bit rate.

In SPI, which device generates the clock signal (SCLK)?

Answer: The master device exclusively

In SPI, only the master generates the clock; slaves synchronize data transmission and reception to this clock.

What is the maximum number of devices addressable on a standard I2C bus using 7-bit addressing?

Answer: 112

7-bit addressing provides 128 possible addresses, but 16 are reserved, leaving 112 usable addresses for slave devices.

CAN bus is most commonly used in which application domain?

Answer: Automotive and industrial control networks

CAN (Controller Area Network) was designed for automotive ECU networks and is widely used in industrial automation due to its noise immunity and multi-master support.

In UART framing, what is the purpose of the stop bit?

Answer: To signal the end of a data frame and allow receiver re-synchronization

The stop bit (logic HIGH) terminates each frame, giving the receiver time to process the byte before the next start bit (logic LOW) arrives.