Recall & Review
beginner
What is a GPIO port-wide operation?
A GPIO port-wide operation means controlling or reading all pins of a GPIO port at once, instead of handling pins individually. It allows faster and simpler manipulation of multiple pins together.
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beginner
How do you set all pins of a GPIO port to high in embedded C?
You write a value with all bits set to 1 to the port's output register. For example, if the port is 8 bits wide, writing 0xFF sets all pins high.
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intermediate
Why use port-wide operations instead of pin-by-pin control?
Port-wide operations are faster and use less code because they change multiple pins at once. This is useful for tasks like turning on many LEDs or reading many buttons simultaneously.
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intermediate
What is a common register used for port-wide GPIO operations?
The GPIO port output data register (often named GPIOx->ODR) is used to write or read the state of all pins in a port at once.
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intermediate
How can you toggle all pins of a GPIO port at once?
You can XOR the port output register with a mask that has bits set for the pins you want to toggle. For example, GPIOx->ODR ^= 0xFF toggles all 8 pins.
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What does writing 0x00 to a GPIO port output register do?
✗ Incorrect
Writing 0x00 means all bits are zero, so all pins are set to low.
Which register is commonly used for port-wide GPIO output control?
✗ Incorrect
GPIOx->ODR (Output Data Register) controls the output state of all pins in the port.
How do you toggle all pins of a GPIO port at once?
✗ Incorrect
XOR with 0xFF flips all bits, toggling all pins.
Why are port-wide operations preferred over pin-by-pin control?
✗ Incorrect
Port-wide operations change many pins at once, making code faster and simpler.
If you want to set only the lower 4 pins high on an 8-bit port, what value do you write?
✗ Incorrect
0x0F sets bits 0 to 3 high, which are the lower 4 pins.
Explain what a GPIO port-wide operation is and why it is useful.
Think about controlling many lights with one switch.
You got /3 concepts.
Describe how to toggle all pins of a GPIO port using embedded C code.
XOR flips bits from 0 to 1 or 1 to 0.
You got /3 concepts.