APB (Advanced Peripheral Bus) and AHB (Advanced High-Performance Bus) represent two widely employed bus protocols within ARM-based microcontroller and microprocessor systems. These buses play a fundamental role in establishing connections between the CPU (Central Processing Unit) and various peripherals and memory components in the system. The primary distinction between them lies in their intended purposes and inherent characteristics.
AHB is used for high-performance components that require high-speed data transfer and low latency. APB is used for low-power peripherals and slower devices, focusing on minimizing power consumption.
What is AHB (Advanced High-Performance Bus)?
AHB (Advanced High-Performance Bus) serves as a high-speed conduit. It is devised to facilitate high-performance peripherals and memory elements. AHB acts as the conduit that links the CPU to high-speed devices such as primary memory (RAM), caches, and other mission-critical components necessitating extensive bandwidth and minimal latency. This bus stands out for its high bandwidth, capability to support burst transfers and efficient pipelining. It aligns perfectly with devices that have an imperative need for swift and effective data transfer, rendering it highly suitable for pivotal system components.
What is APB (Advanced Peripheral Bus)?
APB (Advanced Peripheral Bus) is tailored for power efficiency. The purpose of APB, however, is oriented toward low-power peripherals and interfaces that do not rely on high-speed data transfers. It acts as the bridge connecting the CPU to relatively slower devices like timers, UARTs (Universal Asynchronous Receiver-Transmitters), GPIO (General Purpose Input/Output), and other peripherals operating at reduced speeds. APB is characterized by its low-power nature and reduced bandwidth, making it the ideal choice for peripherals that can function at lower clock speeds and do not necessitate high-speed data transfers. Its deployment aids in the conservation of power resources and the reduction of the overall energy consumption of the system.