Question 4: UART Receiving a byte Interrupt Hardware The figure below shows a simplified hardware architecture for the UART interrupts sub-system. It is composed of software programmable registers (IM, RIS, MIS, ICR), along with logic gates. In this question you will design a circuit to complete the UART interrupt sub-system hardware. You will then complete software to make use of this simplified UART interrupt sub-system. a) Design a CPRE 281 style digital circuit to place in the “Falling Edge Detector” box of the UART Interrupt sub-system. This will be used to detect when a new UART frame begins to arrive. Recall the start symbol of a UART frame is indicated by the UART RX wire transitioning from high to low (i.e. a falling or negative edge occurs). To keep your circuit simple, use to following assumptions: · Your circuit should pulse the “detect” signal for 1 clock cycle whenever a falling edge on the RX wire occurs. In other words, “detect” should become ‘1’ for exactly one clock cycle. · You are limited to using the following types of components: AND, OR, NOT, XOR, D Flip-Flops · Your circuit should use at least 1 D Flip-Flop, but not more than 2. And you can use at most 4 total components. · Assume anytime the RX wire goes low it will stay low for at least one clock cycle. · Falling Edge Detector o Inputs: UART RX wire, and a clock o Output: detect signal b) Provide code to complete init_UART() and My_UART_Handler(). volatile int flag = 0; // Helper variable int main() { init_UART(); // Initializes the GPIO and UART while (1) { //Print each time a new UART Frame begins if(flag == 1) { printf(“Starting to Receive a new UART Frame \n”); flag = 0; reset flag. } } return 0; } void init_UART() { // Assume GPIO has already been initialized for you. // Assume all aspects of the UART except interrupts have been // configured for you // Assume the register size of IM, RIS, MIS, and ICR are 1 bit // Assume these register names have been memory mapped so you // can directly assign values to these names. // Place YOUR CODE HERE to enable the Start of Frame Interrupt // Assume the NVIC has been configured for you //Binds UART interrupt requests to My_UART_Handler IntRegister(INT_UART, My_UART_Handler); } // UART ISR (Give code for the ISR) void My_UART_Handler() { // Check if an Interrupt has really occurred // Set flag so main() knows interrupt occurred // clear the Interrupt. }