If your hardware supports it, perform critical calculations in 64-bit (long long) and then cast them back down to 32-bit or 16-bit after the volatile steps are complete. This provides the "headroom" necessary to avoid the range error. Preventing Future Errors To ensure you don't see this code again:
The FPRE004 code is a specific diagnostic flag used by various compilers and digital signal processors (DSPs). It stands for .
Write tests specifically designed to trigger the upper bounds of your fixed-point registers. Conclusion
Unlike floating-point math, where the decimal point can "float" to accommodate very large or very small numbers, fixed-point math uses a set number of digits before and after the decimal. When a calculation results in a number too large for the assigned "container," the system throws an FPRE004. Common Symptoms
Ensure your Q-format is consistent. If you are multiplying two numbers, the result is technically in Q30 . If you try to store that directly back into a Q15 register without a right-shift ( >> 15 ), you will trigger an FPRE004 error immediately. 3. Update Firmware/Drivers
If your hardware supports it, perform critical calculations in 64-bit (long long) and then cast them back down to 32-bit or 16-bit after the volatile steps are complete. This provides the "headroom" necessary to avoid the range error. Preventing Future Errors To ensure you don't see this code again:
The FPRE004 code is a specific diagnostic flag used by various compilers and digital signal processors (DSPs). It stands for .
Write tests specifically designed to trigger the upper bounds of your fixed-point registers. Conclusion
Unlike floating-point math, where the decimal point can "float" to accommodate very large or very small numbers, fixed-point math uses a set number of digits before and after the decimal. When a calculation results in a number too large for the assigned "container," the system throws an FPRE004. Common Symptoms
Ensure your Q-format is consistent. If you are multiplying two numbers, the result is technically in Q30 . If you try to store that directly back into a Q15 register without a right-shift ( >> 15 ), you will trigger an FPRE004 error immediately. 3. Update Firmware/Drivers