ARM CORTEX-M Processors and their bus

 

ARM architecture is a family of RISC-based processor architectures which are licensed by ARM and used for low power embedded devices.

Below is the image of the CORTEX-M3 Reference Manual.

Following are the bus in the processor:

• AHB-AP (Advanced High Performance Bus - Access Port) helps to provide access to registers and peripherals. This is what we use to debug the system
• AHB-Lite is used to access Memory and peripherals
• APB/PPB (Advanced Peripheral Bus/Private Peripheral Bus) are used for interfacing peripherals like UART, SPI, I2C
• ICode, DCode and System bus interfaces are used to interface the external Memory and the peripherals