XC2000 Logic Cell Array Families Overview
Logic Cell Arrays (LCAs) are CMOS integrated circuits with a high density. Three different types of reconfigurable parts make up its user-programmable array architecture: input/output blocks, logic blocks, and interconnect. The designer can create individual logic blocks to implement logic functions, interconnection networks to create larger scale logic functions, and individual I/O blocks to interface to external circuits. The XACT Development System offers automatic routing and interactive graphic design capture. For design verification, it is possible to use both in-circuit and logic simulation.
Data kept in internal static memory cells determines the LCA logic functions and connections. When the device is powered up, configuration data is automatically loaded thanks to on-chip logic. The program data may be stored on a hard drive, floppy disk, or in an EEPROM, EPROM, or ROM on the circuit board. The application can be loaded in a variety of ways to meet different system needs.
Architecture
I/O Blocks, Configurable Logic Blocks, and Programmable Interconnections are just a few of the user-programmable parts that make up the array. The device package pins and the logic array are connected by the I/OBs. The interconnect resources are configured to construct networks that convey logic signals among the blocks, and the CLBs carry out user-specified logic functions.
With the aid of a dispersed array of memory cells, LCA configuration is created. The program used to setup the Logic CellArray is generated by the XACT development system and incorporates logic to implement automatic configuration.
Configuratlon Memory
Programming memory cells that determine the logic functions and connections results in the configuration of the Logic Cell Array. The user logic functions have no bearing on the memory loading procedure.
