METHODS AND APPARATUS FOR REUSING LOOKUP TABLE RANDOM-ACCESS MEMORY (LUTRAM) ELEMENTS AS CONFIGURATION RANDOM-ACCESS MEMORY (CRAM) ELEMENTS

摘要

A programmable integrated circuit may include configuration random-access memory (CRAM) cells and lookup table random-access memory (LUTRAM) cells. The programmable integrated circuit may include a CRAM column and at least two LUTRAM columns, a first portion of which is operable as LUTRAM cells and a second portion of which is reused as CRAM cells. Each of the memory cells have a configuration write port and a read port. The configuration write ports of the first portion may be gated, whereas the configuration write ports of the second portion lack gating logic. The read port of the memory cells in the LUTRAM columns may be masked only when the first portion of cells are operated in RAM mode and are currently being accessed.