Explain HSE and HSI clock sources? what clock range are available? What does PLL do in the clock circuitry? Describe how to enable the APB2 peripheral (where port E is located) clock. Give the codes in assembly and in C. Configure Port E pin8-15 as 8 output open drain. Give the configuration codes in assembly and in C. Write a C statement to clear the bit 0, bit 1, bit 31 of an IO control register named "SomeReg". The rest of the register bits remain unchanged. Why head file "stm32flox_cl.h" is needed in your C program? What are defined in the file? For the function used in the lecture, find out the parameter passing for a, b and c. int sum (int a, int b) { int c: c = a + b: return c: } what are defined in "STM32F10x_s" startup file? Try to understand them