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
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
If your max value is 32767 and your result is 32800, saturation logic keeps it at 32767. 2. Review Scaling Factors (Q-Format)
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:
Are you dealing with this error in a or on a particular piece of hardware ? Knowing the environment helps narrow down the exact syntax for the fix.
The most robust "FPRE004 fixed" strategy involves saturation. Instead of letting a number "roll over" (where a very large positive number suddenly becomes a very large negative number), saturation forces the value to stay at the maximum allowable limit.
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
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 fpre004 fixed
If your max value is 32767 and your result is 32800, saturation logic keeps it at 32767. 2. Review Scaling Factors (Q-Format) Ensure your Q-format is consistent
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: Common Symptoms If your max value is 32767
Are you dealing with this error in a or on a particular piece of hardware ? Knowing the environment helps narrow down the exact syntax for the fix.
The most robust "FPRE004 fixed" strategy involves saturation. Instead of letting a number "roll over" (where a very large positive number suddenly becomes a very large negative number), saturation forces the value to stay at the maximum allowable limit.