Look-ahead circuit for CSD-code carry determination

Although CSD coding allows for minimal quasiternary representation of any binary number, this code has been used in a small number of applications. Surely this is connected with the fact that this code can be generated only recursively from the least-significant to the most-significant bit. As a consequence of this disadvantage, in most applications the nonminimal modified Booth recoding is preferred, because it can be generated in parallel. The authors introduce a look-ahead method speeding up the generation of the CSD code. By using the CSD code instead of any other quasiternary code, reduced hardware expenditure and reduced power dissipation can be expected due to the minimal number of covered digits