UART protocol fundamentals in Embedded C - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize UART baud rate register.

Embedded C

UART_BAUD_REG = [1];

Drag options to blanks, or click blank then click option'

A103

B9600

C115200

D0xFF

Attempts:

3 left

💡 Hint

Common Mistakes

Using baud rate number directly instead of register value.

The baud rate register value for 9600 baud at 16 MHz clock is 103.

2fill in blank

medium

Complete the code to enable UART transmitter.

Embedded C

UART_CTRL_REG |= [1];

Drag options to blanks, or click blank then click option'

A0x08

B0x04

C0x10

D0x01

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing transmitter enable with receiver enable bits.

Bit 2 (0x04) enables the UART transmitter in control register.

3fill in blank

hard

Fix the error in the UART receive function to correctly check data ready flag.

Embedded C

if (UART_STATUS_REG & [1]) {
    received_data = UART_DATA_REG;
}

Drag options to blanks, or click blank then click option'

A0x20

B0x80

C0x40

D0x10

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong status flag bit causing missed data reception.

Bit 6 (0x40) is the RX complete flag indicating data is ready to read.

4fill in blank

hard

Fill both blanks to create a UART transmit function that waits until ready and sends data.

Embedded C

while (!(UART_STATUS_REG & [1])) {}
UART_DATA_REG = [2];

Drag options to blanks, or click blank then click option'

A0x20

Bdata

C0x80

D0x40

Attempts:

3 left

💡 Hint

Common Mistakes

Waiting on wrong flag or writing wrong variable to data register.

Wait for transmit buffer empty flag (bit 5, 0x20) before writing data to UART_DATA_REG.

5fill in blank

hard

Fill all three blanks to create a UART initialization function setting baud rate, enabling transmitter and receiver.

Embedded C

void UART_Init() {
    UART_BAUD_REG = [1];
    UART_CTRL_REG = [2] | [3];
}

Drag options to blanks, or click blank then click option'

A103

B0x04

C0x08

D9600

Attempts:

3 left

💡 Hint

Common Mistakes

Using baud rate number directly, forgetting to enable both transmitter and receiver.

Set baud rate register to 103 for 9600 baud, enable transmitter (0x04) and receiver (0x08) bits in control register.