Embedded Systems Architecture

Adjusting the flash wait states

If the initialization code is running from flash, it might be necessary to set the wait state for the flash memory before altering the system clocks. If the microprocessor runs at high frequencies, it might require a few wait states in between two consecutive access operations to persistent memory with XIP capabilities. Failing to set the correct wait states, and matching the ratio between the CPU speed and the access time of the flash, would most likely result in a hard fault. The configuration registers for the flash memory are located in a platform-specific location within the internal peripheral's region. On STM32F407, the flash configuration registers are mapped starting at address 0x40023800. The Access ...