  To overcome the limitations of conventional floating-point number formats, an
interval arithmetic and variable-width storage format called universal number
(unum) has been recently introduced. This paper presents the first (to the best
of our knowledge) silicon implementation measurements of an
application-specific integrated circuit (ASIC) for unum floating-point
arithmetic. The designed chip includes a 128-bit wide unum arithmetic unit to
execute additions and subtractions, while also supporting lossless (for
intermediate results) and lossy (for external data movements) compression units
to exploit the memory usage reduction potential of the unum format. Our chip,
fabricated in a 65 nm CMOS process, achieves a maximum clock frequency of 413
MHz at 1.2 V with an average measured power of 210 uW/MHz.

Hardware Architecture