Hybrid product term and LUT based architectures using embedded memory blocks

The Embedded System Block (ESB) of the APEX20K programmable logic device family from Altera Corporation includes the capability of implementing product term macrocells in addition to flexibly configurable ROM and dual port RAM. In product term mode, each ESB has 16 macrocells built out of 32 product terms with 32 literal inputs. The ability to reconfigure memory blocks in this way represents a new and innovative use of resources in a programmable logic device, requiring creative solutions in both the hardware and software domains. The architecture and features of this Embedded System Block are described