From this section, algorithms that were not described in Francis's book [1] are explained. Rmap was developed by Schlag et al of University of California, Santa Cruz. It placed emphasis on the routability of the design. In [2] it is said that only 80% of cells can be routably mapped in typical cases. They viewed routability and CLB counts as a trade-off problem; a routable design with little more CLB's is more preferable than a design with fewer CLB's that is difficult (or impossible) to route. To achieve routable mapping, the ratio of pin-per-cell is used for the measurement of the amount of traffic around the cell. The higher the ratio, the more difficult to route. While other steps of rmap look similar to other algorithm, the main feature of rmap is that it performs covering and cell packing ( merging in mis-pga) simultaneously. In terms of CLB count, rmap out performed chortle-crf in 11 out of 20 MCNC benchmark circuits (in 4 circuits, results of both algorithm were the same). Rmap, chortle-crf and Xnfmap were compared to see the routability of their generated mapping. Rmap out performed in all of 6 ``difficult-to-route'' circuits. It is reported in [7] that rmap is typically five times slower than chortle-crf, but this is not a big problem as placement and routing consumes much longer time.
