1. LEDs are connected as shown in Figure 1. Assume that pins connected to LEDs have been configured as outputs. Given a fragment of microcontroller memory map below determine the status of LED D3 (ON or OFF) after the following Code:
*(uint32_t *) 0x4800 0c14 = 0x00000000;
*(uint32_t *) 0x4800 0c14 = 0x00000040;
LED D3:
Based on the memory map fragment and the given code, the status of LED D3 can be determined as follows:
1. *(uint32_t *) 0x4800 0c14 = 0x00000000;
This line of code is writing the hexadecimal value 0x00000000 to the memory address 0x48000c14. This means all bits in the memory address are set to 0.
2. *(uint32_t *) 0x4800 0c14 = 0x00000040;
This line of code is writing the hexadecimal value 0x00000040 to the memory address 0x48000c14. This means the 7th bit (counting from 0) of the memory address is set to 1, while all other bits are set to 0.
Given that the LEDs are connected as shown in Figure 1, it can be inferred that LED D3 is connected to the 7th bit of the memory address 0x48000c14. When the 7th bit is set to 1 (as in the second line of code), LED D3 will be ON. Therefore, after the second line of code, LED D3 will be ON.
The answers says off
I apologize for the confusion in my previous response. Let's analyze the code and memory map again to determine the correct status of LED D3.
1. *(uint32_t *) 0x48000c14 = 0x00000000;
This line of code writes the hexadecimal value 0x00000000 to the memory address 0x48000c14. All bits in the memory address are set to 0 after this operation.
2. *(uint32_t *) 0x48000c14 = 0x00000040;
This line of code writes the hexadecimal value 0x00000040 to the memory address 0x48000c14. This means that the 6th bit of the memory address is set to 1, while all other bits remain 0.
Based on this analysis, LED D3 is connected to the 6th bit of the memory address 0x48000c14. Since the 6th bit is set to 1 after the second line of code, LED D3 will be ON.
Therefore, the correct status of LED D3 after the given code is ON.
Figure 1:
GPIOD0 --> R1 (430 ohms) --> led --> 3.3V
GPIOD3 --> R2 (430 ohms) --> led --> ground
GPIOD9 --> R3 (430 ohms) --> led --> same ground as GPIOD3
Thank you for providing the additional information about the connections of the LEDs in Figure 1. Given the setup you have described, with LED D3 connected to GPIOD3 through a resistor to ground, we can revisit the analysis to determine the correct status of LED D3 after the given code.
1. *(uint32_t *) 0x48000c14 = 0x00000000;
This line sets all bits at memory address 0x48000c14 to 0.
2. *(uint32_t *) 0x48000c14 = 0x00000040;
This line sets the 6th bit at memory address 0x48000c14 to 1, with other bits as 0.
Based on the new information and the circuit connections provided, LED D3 is connected to GPIOD3 with a resistor to ground. When the 6th bit of memory address 0x48000c14 is set to 1 (as in the second line of code), current flows through the LED and the resistor R2, causing LED D3 to light up. Therefore, the correct status of LED D3 after the given code is ON.