HIERARCHICAL LOCATION CONSTRAINTS FOR PROGRAMMABLE LAYOUTS

Methods for designating target locations for circuit elements to be implemented in a programmable system. A target system is divided into blocks at various levels of hierarchy, with each block within the same higher-level block having a different identifier. A user can specify a desired location for a circuit element at any or all of these levels of hierarchy. Preferably, a desired location is specified using a single location constraint comprising a string of identifiers separated by delimiters. In one embodiment, a uniform coordinate system is applied to all blocks at a given level, even in a non-uniform programmable array. In this embodiment, a non-uniform array of logic blocks is divided into tiles, and a uniform coordinate system is applied to the tiles. Thus, any tile in the array can be addressed using a uniform coordinate system, regardless of the nature of the logic blocks comprising the tile.