Problem executing RIFFT in Cortex-M4

1. Is Cortex-M4 RISC?
2. Is Cortex-M4 RISC or CISC?
3. How many exceptions does the Cortex-M4 processor have?

Is Cortex-M4 RISC?

The ARM Cortex-M is a group of 32-bit RISC ARM processor cores licensed by Arm Holdings.

Is Cortex-M4 RISC or CISC?

Like the Arm Cortex-M4, it is a 32-bit CPU based on a RISC architecture. RISC, or Reduced Instruction Set Computing, is a philosophy of computer architecture that asserts that a small set of simple instructions results in more efficient execution than a larger set of more complex instructions.

How many exceptions does the Cortex-M4 processor have?

Six exceptions are always supported and depending on the Cortex-M variant, additional handlers will be implemented as well. The minimum set is: Reset - This is the routine executed when a chip comes out of reset.