Reviewing High-Radix Signed Digit Adders

Peter Kornerup

Publikation: Bidrag til tidsskriftReviewForskningpeer review


Higher radix values of the form $\beta=2^r$ have been employed
traditionally for recoding of multipliers, and for determining quotient-
and root-digits in iterative division and square root algorithms, usually
only for quite moderate values of $r$, like 2 or 3. For fast additions,
in particular for the accumulation of many terms, generally redundant
representations are employed, most often binary carry-save or
borrow-save, but in a number of publications it has been suggested to
recode the addends into a higher radix. It is shown that there are no
speed advantages in doing so if the radix is a power of~2, on the
contrary, there are significant savings in using standard 4-to-2 adders,
even saving half of the operations in multi-operand addition.
TidsskriftI E E E Transactions on Computers
Udgave nummer5
Sider (fra-til)1502-1505
StatusUdgivet - 1. maj 2015


  • Multi-operand addition, Signed Digit, Carry-Save, High-Radix