Logic block

In computing, a logic block or configurable logic block (CLB) is a fundamental building block of field-programmable gate array (FPGA) technology. Logic blocks can be configured by the engineer to provide reconfigurable logic gates.

Logic blocks are the most common FPGA architecture, and are usually laid out within a logic block array. Logic blocks require I/O pads (to interface with external signals), and routing channels (to interconnect logic blocks).

Programmable logic blocks were invented by David W. Page and LuVerne R. Peterson, and defined within their 1985 patents.