AM62x MCU+ SDK  08.04.00


NORTOS is a SW module that implements APIs which allow the upper layers of SW to run in no-RTOS mode. i.e without any RTOS. The NO RTOS APIs are implemented underneath the Driver Porting Layer (DPL) APIs. This allows the device drivers to run either in no-RTOS mode or with a RTOS.

Features Supported

Common across all CPUs,

  • Clock APIs to initialize a system tick ISR and allow SW to create multiple SW timers using a single underlying HW timer.
  • Address translate APIs to translate system address to local address, needed for M4F
  • Heap APIs to create arbitrary heaps at user defined memory locations
  • Semaphore APIs to model a semaphore in no-RTOS environment
  • HW Timer APIs to setup user defined HW timers beyond the system tick timer.
  • Logging APIs to log to different consoles like UART, CCS, shared memory, CPU local memory, including logging zones to enable/disable logging.

M4F features,

  • CPU start up code
  • Memory protection unit (MPU) APIs to enable, disable multiple regions in the MPU
  • Interrupt controller APIs to register ISRs, enable/disable interrupts
  • ISR handlers and exception handlers
  • Performance counter APIs
  • SysTick timer APIs
  • M4F ISRs
    • Nested interrupts

SysConfig Features

It is strongly recommend to use SysConfig where it is available instead of using direct SW API calls. This will help simplify the SW application and also catch common mistakes early in the development cycle.

SysConfig can be used to configure below modules with NORTOS

  • Clock module to setup system tick timer including the tick duration
  • Debug Log module to select the console to use for logging as well as enable/disable logging zones
  • MPU ARMv7 to setup different MPU regions for R5F and M4F CPUs
  • RAT to setup address translation regions, needed for M4F
  • Timer to setup HW timer available on the SOC, including enabling timer interrupt and ISR registration

Features Not Supported

  • Task APIs are not supported in NORTOS mode. Task APIs necessarily need a RTOS and cannot be used in no-RTOS mode
  • M4F ISRs,
    • FPU save/restore not supported.

Important files and directory structure

Folder/Files Description
dpl/ APIs to access NORTOS features
lib/ NORTOS library to link against. Linking to the library in this path enables the application to operate in no-RTOS mode

NORTOS APIs that are common across all CPUs


NORTOS APIs that are specific to M4F CPUs

Additional References

Precise web links are not provided since these can change, search for the document title in google to download the documents

Please also refer to below documents from ARM Ltd. to understand more about R5F, M4F, A53 CPUs including features like MPU, MMU, cache and interrupts.

Document Title


ARM v7M Architecture Reference Manual

Information about ARM architecture that is implemented by M4F. Should be used in conjunction with M4F TRM to understand M4F architecture details.

ARM Cortex M4F Technical Reference Manual

Information about M4F CPU architecture.

See also

Driver Porting Layer (DPL)