Introduction  In the quest for accurate and efficient signal estimation

Universal Serial Bus popularly known as USB is a Plug and Play interface used for computers to communicate with diverse types of USB peripherals. Keyboards, Mouses, Joysticks, Speakers, Webcams, External Drives are common USB devices. The underlying mechanisms for each of these devices are different. Some of them are mass storage devices, video devices, audio devices while others are human interface devices. UVC stands for USB Video Class and can transmit video over USB, similarly UAC stands for USB Audio Class and can transmit audio over USB. When user plugs a UVC/UAC device to the host, configuration, and enumeration of UVC/UAC device at host will be completed and its capabilities advertised to the host. USB Camera and USB Headset is an example of UVC and UAC Device, respectively.

Cache coherence maintains consistency between cached data copies when multiple devices access shared memory. This blog explores the need for cache coherency, coherence protocols like snooping, and fixing incoherence issues in multicore systems like ensuring descriptor writebacks for proper DMA transfers with EMAC.