The floating-point status word (FPSW) indicates the results of floating-point operations. In products that do not support floating-point instructions, the value "00000000h" is always read out and writing to these bits does not affect operations.
When an exception handling enable bit (Ej) enables the exception handling (Ej = 1), the corresponding Cj flag indicates the cause. If the exception handling is masked (Ej = 0), check the Fj flag at the end of a series of processing. The Fj flag is the accumulation type flag (j = X, U, Z, O, or V).