AN4141 Datasheet, PDF (7/42 Pages) STMicroelectronics – Migration and compatibility guidelines for STM32W108xx microcontroller applications based on the HAL

AN4141
Why migrate from HAL to StdPeriph_Lib?
1.1.1
1.1.2
CMSIS description
As part of the CMSIS, ARM provides the following software layers, which are available for
various compiler implementations:
• Core peripheral access layer: contains name definitions, address definitions and
helper functions to access core registers and peripherals. It also defines a device-
independent interface for RTOS kernels that includes debug channel definitions.
• Device peripheral access layer: provides definitions for all device peripherals.
For a Cortex-Mx microcontroller system, CMSIS defines:
• A common way of accessing peripheral registers and a common way of defining
exception vectors
• Register names of the core peripherals and names of the core exception vectors
• A device-independent interface for RTOS kernels, including a debug channel
• Interfaces for middleware components (TCP/IP stack, flash file system)
CMSIS structure
Figure 1 illustrates different layers for a CMSIS-based application.
Figure 1. CMSIS layer structure
Application code
Real-time
kernel
Middleware
components
Core peripheral
functions
Middleware access Device peripheral
functions
functions
Peripheral register & interrupt vector definitions
Cortex
CPU
SysTick
RTOS kernel
timer
NVIC
nested vector
interrupt controller
Debug/Trace
interface
Other
peripherals
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