Programmable logic device having logic elements with dedicated hardware to configure look up tables as registers
First Claim
1. A programmable logic device, comprising:
- a general interconnect;
a plurality of logic array blocks (LAB) interconnected by the general interconnect;
each of the plurality of logic blocks further comprising one or more logic elements, each of the logic elements comprising;
a first look up table configured to generate an output signal, the first look up table having a first look up table input;
a second look up table configured to receive the output signal as input;
dedicated hardware within the logic element to configure the first look up table and the second look up table as a register without having to use the general interconnect;
a selection device coupled to the first look up table input and configured to select between the output signal and another signal to provide the selection to the first look up table input,wherein the dedicated hardware includes a first dedicated interconnect providing a clock signal as an input to the first look up table and the second look up table respectively, wherein the first dedicated interconnect is connected to a LAB wide interconnect of the logic block,wherein the first look up table is physically arranged above the second look up table in the logic block, the dedicated hardware further configured to cascade the register formed from the first look up table and the second look up table with a second register provided in the logic block.
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Accused Products
Abstract
A programmable logic device architecture having logic elements with dedicated hardware to configure the look up tables of the logic element to either perform logic functions or to operate as a register for pipelining or other purposes. The programmable logic device includes a general interconnect and a plurality of logic array blocks interconnected by the general interconnect. Each of the plurality of logic blocks further includes one or more logic elements. The logic elements each include a first look up table, a second look up table, and dedicated hardware within the logic element to configure the first look table and the second look up table as a register without having to use the general interconnect. In one embodiment, the dedicated hardware includes a plurality of dedicated interconnects within the logic element to configure the two look up tables as a pair of cross coupled muxes or latches when configured as a register.
12 Citations
24 Claims
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1. A programmable logic device, comprising:
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a general interconnect; a plurality of logic array blocks (LAB) interconnected by the general interconnect; each of the plurality of logic blocks further comprising one or more logic elements, each of the logic elements comprising; a first look up table configured to generate an output signal, the first look up table having a first look up table input; a second look up table configured to receive the output signal as input; dedicated hardware within the logic element to configure the first look up table and the second look up table as a register without having to use the general interconnect; a selection device coupled to the first look up table input and configured to select between the output signal and another signal to provide the selection to the first look up table input, wherein the dedicated hardware includes a first dedicated interconnect providing a clock signal as an input to the first look up table and the second look up table respectively, wherein the first dedicated interconnect is connected to a LAB wide interconnect of the logic block, wherein the first look up table is physically arranged above the second look up table in the logic block, the dedicated hardware further configured to cascade the register formed from the first look up table and the second look up table with a second register provided in the logic block. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 23, 24)
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12. A method comprising:
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interconnecting a plurality of logic array blocks (LABs) by using a general interconnect, one of the logic array blocks comprises at least one logic element; receiving an output signal by a first look up table of one of the at least one logic element, said receiving the output signal is performed by a second look up table of the one of the at least one logic element; configuring the first look table and the second look up table as a register without having to use the general interconnect, said configuring the first look up table and the second look up table as a register is performed by using dedicated hardware within the one of the at least one logic element; selecting between the output signal and another signal to provide the selection to a single input of the first look up table; communicating a clock signal as an input to the first look up table and the second look up table respectively, said communicating the clock signal as the input to the first look up table and the second look up table respectively is performed using a first dedicated interconnect of the dedicated hardware, wherein the first dedicated interconnect is connected to a LAB wide interconnect of one of the logic array blocks; physically arranging the first look up table above the second look up table in the logic block, the dedicated hardware further configured to cascade the register formed from the first look up table and the second look up table with a second register in the logic block. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification