摘要:
A logic element for a programmable logic device. The logic element includes a look-up table (400) for implementing logical functions, a programmable delay block (415), a storage block (430) configurable as a latch or a flip-flop, and a diagnostic shadow latch (435). A plurality of inputs (410) to the logic element and complements of these inputs are available to control the secondary functions of the storage block (430).
摘要:
A programmable logic device (PLD) that provides the capability to observe and control the logic state of buried internal nodes is disclosed. The PLD provides shadow storage units for internal nodes such as logic element registers, memory cells, and I/O registers. A sample/load data path includes bidirectional data buses and shift register that facilitate the sampling of internal nodes for observing their logic states, and loading of internal nodes for controlling their logic states.
摘要:
A programmable logic device is provided that contains a plurality of logic array blocks arranged in rows and columns. The logic array blocks are interconnected with horizontal conductors in each row and vertical conductors in each column. The logic array blocks and the interconnections between conductors are configured using programmable logic. Some of the programmable logic is used to selectively connect logic array block input terminals to the horizontal conductors. Additional logic in each column is used to selectively connect the horizontal conductors to either logic array block output terminals from the same column or logic array block output terminals from an adjacent column. The additional logic prevents certain interconnection pathways from being blocked and increases the overall flexibility of the interconnection scheme of the programmable logic device, thereby improving device performance.