这是我大学的倒数第二个学期，这门课叫微处理器的体系结构和编程，教授写了这段代码，我就是不明白他在做什么。特别是带面具的部分。这是代码。谁能帮我理解一下吗？

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

uint32_t Instruction_Memory[0x2000];
uint32_t PC = 0;

uint32_t Registers[32];

uint32_t Data_Memory[0x3000];

uint32_t get_instruction(uint32_t input){
   uint32_t temp = input/4;
   return Instruction_Memory[temp];
}

void print_registers() {
   for (int i = 0; i < 4; i++) {
       for (int j = 0; j < 8; j++) {
           printf("x%d: %x \t", i*8+j, Registers[i*8+j]);
       }
       printf("\n");
   };
};

uint32_t get_bits(uint32_t input, int start, int numberOfBits){
   uint32_t t4 = input >> start;
   uint32_t mask = (1 << numberOfBits) - 1;

   t4 = mask & t4;
//    printf("input : %x, start : %d, nob : %d, mask : %x\n", input, start, numberOfBits, mask);
   return t4;
}

int main(){

   PC = 0x1000;

//    x5
   Registers[5] = 6;
//    x9
   Registers[9] = 0x2004;

   Data_Memory[0x2000] = 10;

   Instruction_Memory[0x1000 / 4] = 0xFFC4A303;
   Instruction_Memory[0x1004 / 4] = 0x0064A423;
   Instruction_Memory[0x1008 / 4] = 0x0062E233;

   uint32_t instruction = get_instruction(0x1000);

   printf("Instruction = 0x%x\n\r", instruction);

   print_registers();
   uint32_t A1 = get_bits(instruction, 15, 5);
   printf("A1 = %x\n\r", A1);

   return 0;
}

据我所知，他打印出了登记册，并向系统提供了一个指令。