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Q1. 20pts Consider a C program for an Atmel AVR that uses a UART to send 8 bytes to an RS-232 serial interface, as follows: 1: for (i=0; i<8; i++) { 2: while (!(UCSR0A & 0x20)); 3: UDR0 = x[i]; 4: } Assume the processor runs at 50 MHz; also assume that initially the UART is idle, so when the code begins executing, UCSR0A & 0x20 == 0x20 is true; further, assume that the serial port is operating at 19,200 baud. How many cycles are required to execute the above code? You may assume that the for statement executes in three cycles (one to increment i, one to compare it to 8, and one to perform the conditional branch); the while statement executes in two cycles (one to compute !(UCSR0A & 0x20) and one to perform the conditional branch); and the assignment to UDR0 executes in one cycle. In addition, you can assume that the number of cycles required to send start and stop bits is negligible and the time to transmit 1 byte data and the time to satisfy the condition of the while statement are almost the same (to simplify this question).

          Q1. 20pts Consider a C program for an Atmel AVR that uses a UART to send 8 bytes to an RS-232 serial interface, as follows:

1: for (i=0; i<8; i++) {
2: while (!(UCSR0A & 0x20));
3: UDR0 = x[i];
4: }

Assume the processor runs at 50 MHz; also assume that initially the UART is idle, so when the code begins executing, UCSR0A & 0x20 == 0x20 is true; further, assume that the serial port is operating at 19,200 baud. How many cycles are required to execute the above code?

You may assume that the for statement executes in three cycles (one to increment i, one to compare it to 8, and one to perform the conditional branch); the while statement executes in two cycles (one to compute !(UCSR0A & 0x20) and one to perform the conditional branch); and the assignment to UDR0 executes in one cycle.

In addition, you can assume that the number of cycles required to send start and stop bits is negligible and the time to transmit 1 byte data and the time to satisfy the condition of the while statement are almost the same (to simplify this question).

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Q1. 20pts Consider a C program for an Atmel AVR that uses a UART to send 8 bytes to an RS-232 serial interface, as follows:

1: for (i=0; i<8; i++)
2: while (!(UCSR0A 0x20));
3: UDR0 = x[i];
4:

Assume the processor runs at 50 MHz; also assume that initially the UART is idle, so when the code begins executing, UCSR0A 0x20 == 0x20 is true; further, assume that the serial port is operating at 19,200 baud. How many cycles are required to execute the above code?

You may assume that the for statement executes in three cycles (one to increment i, one to compare it to 8, and one to perform the conditional branch); the while statement executes in two cycles (one to compute !(UCSR0A 0x20) and one to perform the conditional branch); and the assignment to UDR0 executes in one cycle.

In addition, you can assume that the number of cycles required to send start and stop bits is negligible and the time to transmit 1 byte data and the time to satisfy the condition of the while statement are almost the same (to simplify this question).

Added by Zachary T.

Computer Science and Information Technology

Trishna Knowledge Systems 2018 Edition

Instant Answer

Solved by Expert Akash M

11/19/2023

Step 1

The for loop executes 8 times (for each byte to be sent). Show more…

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