Formalization of Cadence SPW Fixed-Point Arithmetic in
HOL
Behzad Akbarpour, Sofiène
Tahar and Abdelkader Dekdouk
ABSTRACT
In this report we propose the formalization in higher-order logic of fixed-point
arithmetic based on the SPW (Signal Processing WorkSystem) tool. We encoded the
fixed-point number system and specified the different rounding modes in
fixed-point arithmetic such as the directed and even rounding modes. We also
considered the formalization of exceptions detection and their handling like
overflow and invalid operation. An error analysis is then performed to check the
correctness of the rounding and to verify the basic arithmetic operations,
addition, subtraction, multiplication and division against their mathematical
counterparts. Finally, we showed by an example how this formalization can be
used to enable the verification of the transition from the floating-point to
fixed-point algorithmic levels in the design flow of signal processors.