Embedded memory block with FIFO mode for programmable logic device
First Claim
Patent Images
1. A configurable logic block in a programmable logic device integrated circuit comprising:
- a memory array, wherein said memory array comprises a plurality of memory cells arranged in a random access memory format and address lines to address each of said plurality of memory cells;
a first register coupled to said address lines of said memory array, wherein in a FIFO mode, said configurable logic block operates as a first-in, first-out memory and said first register contains a write address;
a second register coupled to said address lines of said memory array, wherein in said FIFO mode, said second register contains a read address; and
a local interconnect having a plurality of conductors which are programmably coupled to said memory array, said first register, and said second register, wherein said first and second registers are coupled to said address lines of said memory array without passing through said local interconnect.
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Abstract
An programmable logic device has an enhanced embedded array block for the efficient implementation of logic functions including a random access memory and a first-in, first-out memory. A read address register and a write address register are implemented within the embedded array block. The address registers are coupled with a memory array in the embedded array block without using a resources from a programmable interconnect scheme. The first-in, first-out memory may operate as a dual-port FIFO, without cycle-sharing on the interconnect lines.
143 Citations
50 Claims
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1. A configurable logic block in a programmable logic device integrated circuit comprising:
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a memory array, wherein said memory array comprises a plurality of memory cells arranged in a random access memory format and address lines to address each of said plurality of memory cells; a first register coupled to said address lines of said memory array, wherein in a FIFO mode, said configurable logic block operates as a first-in, first-out memory and said first register contains a write address; a second register coupled to said address lines of said memory array, wherein in said FIFO mode, said second register contains a read address; and a local interconnect having a plurality of conductors which are programmably coupled to said memory array, said first register, and said second register, wherein said first and second registers are coupled to said address lines of said memory array without passing through said local interconnect. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A programmable integrated circuit comprising:
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an interconnect grid comprising a plurality of horizontal conductors and a plurality of vertical conductors, wherein said vertical conductors may be programmably coupled to said horizontal conductors; a plurality of logic array blocks programmably coupled to said interconnect grid; and an embedded array block, programmably coupled to said interconnect grid, wherein said embedded array block is configurable as a RAM in a RAM mode and a FIFO in a FIFO mode and comprises; a memory array, wherein said memory array comprises a plurality of memory cells arranged in a random access memory format and address lines to address said memory array; a first register coupled to said address lines of said memory array, wherein said first register stores a write address when said embedded array block is in said FIFO mode; a second register coupled to said address lines of said memory array, wherein said second register stores a read address when said embedded array block is in said FIFO mode; and a local interconnect, wherein said local interconnect is programmably coupled to said interconnect grid, first register and said second register, and said first register and second register are coupled to said address lines of said memory array without passing through said local interconnect. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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26. A programmable integrated circuit comprising:
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an interconnect grid; a first array block, programmably coupled to said interconnect grid; a second array block, programmably coupled to said interconnect grid, is configurable as a RAM in a RAM mode and a FIFO in a FIFO mode, said second array block comprising; a memory array, said memory array having a plurality of memory cells arranged in a random access memory format and address lines to address said memory array; a first register coupled to said address lines of said memory array, said first register containing a write address when said second array block is in said FIFO mode; a second register coupled to said address lines of said memory array, said second register containing a read address when said second array block is in said FIFO mode; and a local interconnect, said local interconnect being programmably coupled to said interconnect grid, first register, and second register, wherein said first register and said second register are coupled to said address lines of said memory array without passing through said local interconnect. - View Dependent Claims (27, 28, 29)
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30. A programmable integrated circuit comprising:
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an interconnect grid comprising a plurality of horizontal conductors and a plurality of vertical conductors, wherein said vertical conductors may be programmably coupled to said horizontal conductors; a plurality of logic array blocks programmably coupled to said interconnect grid; and an embedded array block, programmably coupled to said interconnect grid wherein said embedded array block is configurable as a RAM in a RAM mode and a FIFO in a FIFO mode and said embedded array block comprises; a memory array, wherein said memory array comprises a plurality of memory cells arranged in a random access memory format and address lines to address said memory array; a first register coupled to said address lines of said memory array, wherein said first register stores a write address when said embedded array block is in said FIFO mode; a second register coupled to said address lines of said memory array, wherein said second register stores a read address when said embedded array block is in said FIFO mode; and a local interconnect, wherein said local interconnect is programmably coupled to said interconnect grid, first register, and second register, wherein one of said plurality of logic array blocks is configured to duplicate said first register and said second register, and to provide a status flag representative of a status of said memory array. - View Dependent Claims (31, 32, 33, 34, 35, 36, 37, 38, 39)
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40. A programmable logic integrated circuit comprising:
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a programmable interconnect array; a plurality of configurable logic blocks programmably coupled to the programmable interconnect array; and a plurality of configurable memory blocks, programmably coupled to the programmable interconnect array, wherein a configurable memory block is operable as a random access memory in a RAM mode and a first-in, first-out memory in a FIFO mode and comprises; a local interconnect; a memory array comprising a read address input and write address input; a first register coupled to the local interconnect, wherein in the FIFO mode, the first register stores a write address and is coupled to the read address input of the memory array without passing through the local interconnect; and a second register coupled to the local interconnect, wherein in the FIFO mode, the second register stores a read address and is coupled to the write address input of the memory array without passing through the local interconnect. - View Dependent Claims (41, 42, 43, 44, 45, 46, 47, 48, 49, 50)
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Specification