Audio Processing Series Part II : Storing Audio data on external Serial Flash Memory
Storing Audio data in an SPI Flash Memory This is the second article of the Audio Processing Project on the STM32 F411 Discovery Board. This article focuses on developing the SPI driver and the Library for the W25Q64FV 64 M-bit Serial Flash Memory from Winbond. The W25Qxx series of chips are Serial NOR Flash memory devices with capacities ranging from 4 MB to 128 MB and utilize the Serial Peripheral Interface for communication with microcontrollers. Checkout the STM32F411 Reference Manual (RM0383) and the Datasheet for W25Q64FV 64M-bit SPI Flash Memory . Developing the SPI Driver Since some of the SPI1 and SPI3 peripheral pins are already occupied by the JTAG interface on the STM32F411 Discovery Board, we will use the SPI2 peripheral for our communication with the external flash memory. Remember to enable the clock to the GPIO Port B and SPI2 peripheral in the RCC registers. For driving the NSS line Low and High to Select and Deselect the Slave device, we can write functions that set