CMSIS notes

CMSIS: The Common Microcontroller Software Interface Standard

Starting point naming elements of CMSIS:

• https://developer.arm.com/tools-and-software/embedded/cmsis

• https://arm-software.github.io/CMSIS_5/Core/html/index.html

• https://arm-software.github.io/CMSIS_5/Core/html/using_TrustZone_pg.html

In CMSIS file `./modules/hal/cmsis/CMSIS/DSP/Include/arm_math_types.h`:

 503   /**
 504    * @brief Error status returned by some functions in the library.
 505    */
 506 
 507   typedef enum
 508   {
 509     ARM_MATH_SUCCESS        =  0,        /**< No error */
 510     ARM_MATH_ARGUMENT_ERROR = -1,        /**< One or more arguments are incorrect */
 511     ARM_MATH_LENGTH_ERROR   = -2,        /**< Length of data buffer is incorrect */
 512     ARM_MATH_SIZE_MISMATCH  = -3,        /**< Size of matrices is not compatible with the operation */
 513     ARM_MATH_NANINF         = -4,        /**< Not-a-number (NaN) or infinity is generated */
 514     ARM_MATH_SINGULAR       = -5,        /**< Input matrix is singular and cannot be inverted */
 515     ARM_MATH_TEST_FAILURE   = -6         /**< Test Failed */
 516   } arm_status;

Also worth reviewing content of file `arm_math.h`.

2021-11-06 SAT:

To make use of ARM RFFT FAST functions, in Zephyr app must assign 'y' to the Kconfig symbol CONFIG_CMSIS_DSP_TRANSFORM as in this post:

• https://github.com/zephyrproject-rtos/zephyr/issues/32206