AHB Bus and APB Bus

The AHB is primarily used for connections between high-performance modules such as CPUs, DMA, and DSP, and acts as an on-chip system bus for the SOC, which includes the following features: Single clock edge operation, non-tri-state Implementation mode;
Support burst transmission, support segmented transmission, support multiple host controllers, configurable 32-bit ~128-bit bus width, support byte, half-byte and word transmission. The AHB system consists of the main module, the module and the infrastructure
(Infrastructure) 3 parts, the entire AHB bus transmission is issued by the main module, from the module responsible for response. The infrastructure is made up of arbitrators (arbiter), master modules to the multiplexer from the module,
From the module to the main module of the multiplexer, decoder (decoder), virtual slave module (dummy Slave), Virtual Master module (dummy master) composed.
Http://blog.21ic.com/user1/405/archives/2006/20569.html

The AMBA (Advanced microcontroller bus Architecture) Bus specification is a bus standard designed by arm for high-performance embedded systems. It is independent of the processor and manufacturing
Process technology, which enhances the reusability of peripherals and system macro units in a variety of applications. The AMBA Bus specification is an open standard that can be obtained free of charge from arm. At present, AMBA has a number of third-party support and is
With more than 90% of ARM's partners, the ARM processor core-based SOC design has become one of the most widely supported existing interconnect standards. AMBA Bus Specification 2.0 released in 1999, the specification
The introduction of advanced high Performance bus (AHB) is the main form of AMBA implementation at present. The key to AHB is the definition of interfaces and interconnects to achieve the maximum bandwidth of interfaces and interconnects under any process conditions.
The AHB interface is decoupled from the interconnection function and is no longer just a bus, but a interconnect system with interface modules.

?? The AMBA Bus specification is designed for the following purposes: ① meets the rapid development requirements of embedded system products with one or more CPUs or DSPs; ② increases the independence of design technology to ensure reusable
Multiple IP cores can be successfully ported to different systems for full customization, standard cell and gate array technologies; ③ facilitates modular design of the system to increase the independence of the processor; ④ reduces the bottom silicon
To make the off-chip operation and test communication more efficient.

?? Amba Bus is a multi-bus system. The specification defines three different types of buses that can be used together: AHB (Advanced High-performance Bus),
ASB (Advanced System Bus) and APB (Advanced peripheral bus).
Http://www.china-vision.net/blog/user1/6/archives/2006/2006112215720.shtml

APB Bus

APB Profile APB (Advanced peripheral bus), peripheral bus meaning. The bus protocol is one of the AMBA bus structures proposed by arm, which has almost become a standard on-chip bus structure. APB is primarily used for connections between low bandwidth peripheral peripherals, such as UART, 1284, etc., and its bus architecture does not support multiple main modules like AHB, the only main module in the APB is the APB Bridge. Its characteristics include: two clock cycle transmission, no waiting period and response signal, simple control logic, only four control signals. The transmission on the APB can be illustrated by the status diagram shown in 2. 1) The system is initialized to the idle state, there is no transfer operation at this time, and no slave module is selected. 2) When there is a transmission to be carried out, pselx=1,penable=0, the system enters the setup state and only stays in the setup state for a period. When the next rising edge of the PCLK arrives, the system enters the Enable state. 3) When the system enters the Enable state, the PADDR, Psel, pwrite unchanged in the setup state are maintained, and the penable is set to 1. The transfer is also only maintained in the Enable State for a period, after the setup and enable state has been completed. Then, if there is no transmission to proceed, it enters the idle state, and if there is a continuous transmission, it enters the setup state.

AHB is mainly used for the connection between high-performance modules (such as CPU, DMA, DSP, etc.), as the SOC on-chip system bus, which includes the following features: Single clock edge operation, non-tri-State Implementation mode, support burst transmission, support segmented transmission, support multiple host controllers, configurable 32-bit ~ 128-bit bus width, byte, half byte, and word transmission support. The AHB system consists of a master module, a module and an infrastructure (Infrastructure) 3 part, the transmission of the entire AHB bus is issued by the main module, from the module responsible for response. The infrastructure consists of an arbiter (arbiter), a master module, a multiplexer from a module, a multiplexer from a module to a master module, a decoder (decoder), a virtual slave module (dummy Slave), and a virtual Master module (dummy master).
Http://blog.21ic.com/user1/405/archives/2006/20569.html

The AMBA (Advanced microcontroller bus Architecture) Bus specification is a bus standard designed by arm for high-performance embedded systems. It is independent of the processor and manufacturing process technology, enhancing the reusability of peripherals and system macro units in a variety of applications. The AMBA Bus specification is an open standard that can be obtained free of charge from arm. At present, AMBA has a number of third-party support, adopted by more than 90% of ARM's partners, in the ARM processor core-based SOC design, has become widely supported by one of the existing interconnection standards. The AMBA Bus Specification 2.0 was released in 1999, and the Advanced High Performance Bus (AHB) introduced by the specification is the main form of AMBA implementation at this stage. The key to AHB is the definition of interfaces and interconnects to achieve the maximum bandwidth of interfaces and interconnects under any process conditions. The AHB interface is decoupled from the interconnection function and is no longer just a bus, but a interconnect system with interface modules.

?? The AMBA Bus specification is designed for the following purposes: ① meets the rapid development requirements of embedded system products with one or more CPUs or DSPs; ② increases the independence of the design technology, ensures that the reusable IP cores can be successfully ported to different systems, and is suitable for the technology of full customization, standard cell and gate array, etc. ③ Promote the modular design of the system to increase the independence of the processor; ④ reduces the need for the underlying silicon to make the off-chip operation and test communication more efficient.

?? Amba Bus is a multi-bus system. The specification defines three different types of buses that can be used together: AHB (Advanced High-performance Bus), ASB (Advanced System Bus), and APB (Advanced peripheral bus). Http://www.china-vision.net/blog/user1/6/archives/2006/2006112215720.shtml

AHB Bus and APB Bus