Programmable logic device having heterogeneous programmable logic blocks

• US 6,970,012 B2
• Filed: 06/10/2002
• Issued: 11/29/2005
• Est. Priority Date: 06/10/2002
• Status: Active Grant

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Pi, Tao, Crotty, Patrick J.
• Primary Examiner(s): Tran, Anh Q.
• Application Number:
  US10/167,339
• Publication Number:
  US 20040178818A1
• Time in Patent Office: 1,268 Days
• Field of Search: 326 38- 41
• US Class Current: 326/40
• CPC Class Codes: H03K 19/17728 Reconfigurable logic blocks, e.g. lookup tables
• CPC Class Codes: H03K 19/1776 for memories

Abstract

A programmable logic device (PLD) having heterogeneous programmable logic blocks. In one embodiment, the PLD includes programmable interconnect circuitry and programmable input-output circuitry coupled to the programmable interconnect circuitry. An array of programmable logic blocks is coupled to the interconnect circuitry. Each programmable logic block includes a plurality of programmable logic elements coupled to the interconnect circuitry. Each of the programmable logic elements is programmable to implement a common set of functions, and at least one but less than all of the programmable logic elements is programmable to implement a set of supplemental functions.

Claims

1. A programmable logic device comprising:

programmable interconnect circuitry;

programmable input-output circuitry coupled to the programmable interconnect circuitry; and

an array of programmable logic blocks, each logic block including a plurality of programmable logic elements coupled to the interconnect circuitry, wherein each of the programmable logic elements is programmable to implement a common set of functions, and at least one but less than all of the programmable logic elements is programmable to implement a set of supplemental functions, wherein the set of supplemental functions includes a distributed memory function, and selected bits of a distributed memory are stored in a programmable logic element.

2. The programmable logic device of claim 1, wherein the set of supplemental functions includes a shift register function.

3. The programmable logic device of claim 1, wherein each logic block includes an even number of programmable logic elements, and one half of the programmable logic elements in each logic block are programmable to implement the set of supplemental functions.

4. The programmable logic device of claim 3, wherein each programmable logic element includes at least one lookup table having input ports coupled to the interconnect circuitry and programmable to implement a logic function.

5. The programmable logic device of claim 4, wherein each programmable logic element includes at least one storage element having an input port coupled to an output port of a corresponding lookup table and an output port coupled to the interconnect circuitry.

6. The programmable logic device of claim 5, wherein each programmable logic element includes a programmable arithmetic circuit associated with a lookup table and having input ports and output ports, the input ports coupled to the output port of the associated lookup table, the interconnect circuitry, and to an output port of an arithmetic circuit associated with another lookup table, the output ports coupled to an associated storage element, to the interconnect circuitry, and to an arithmetic circuit associated with another lookup table.

7. A programmable logic device comprising:

programmable interconnect circuitry;

programmable input-output circuitry coupled to the programmable interconnect circuitry; and

an array of programmable logic blocks, each logic block including a plurality of programmable logic elements coupled to the interconnect circuitry, wherein at least one of the programmable logic elements in a logic block is programmable to implement a first set of functions, and at least one other of the programmable logic elements in the logic block is programmable to implement a second set of functions that is a proper subset of the first set of functions, wherein a function in the first set and not in the second set is a distributed memory function, wherein selected bits of a distributed memory are stored in a programmable logic element.

8. The programmable logic device of claim 7, wherein a function in the first set and not in the second set is a shift register function.

9. The programmable logic device of claim 7, wherein each logic block includes an even number of programmable logic elements, one half of the programmable logic elements in each logic block are programmable to implement the first set of functions, and one half of the programmable logic elements in each logic block are programmable to implement the second set of functions.

10. The programmable logic device of claim 9, wherein each programmable logic element includes at least one lookup table having input ports coupled to the interconnect circuitry and programmable to implement a logic function.

11. The programmable logic device of claim 10, wherein each programmable logic element includes at least one storage element having an input port coupled to an output port of a corresponding lookup table and an output port coupled to the interconnect circuitry.

12. The programmable logic device of claim 11, wherein each programmable logic element includes a programmable arithmetic circuit associated with a lookup table and having input ports and output ports, the input ports coupled to the output port of the associated lookup table, the interconnect circuitry, and to an output port of an arithmetic circuit associated with another lookup table, the output ports coupled to an associated storage element, to the interconnect circuitry, and to an arithmetic circuit associated with another lookup table.

13. A programmable logic block arrangement, comprising:

a switch circuit;

a plurality of programmable logic elements coupled to the switch circuit, wherein each of the programmable logic elements is programmable to implement a common set of functions, and at least one but less than all of the programmable logic elements is programmable to implement a set of supplemental functions, wherein the set of supplemental functions includes a distributed memory function, and selected bits of a distributed memory are stored in a programmable logic element.

14. The programmable logic block arrangement of claim 13, wherein the set of supplemental functions includes a shift register function.

15. The programmable logic block arrangement of claim 13, wherein each logic block includes an even number of programmable logic elements, and one half of the programmable logic elements in each logic block are programmable to implement the set of supplemental functions.

16. The programmable logic block arrangement of claim 15, wherein each programmable logic element includes at least one lookup table that is programmable to implement a logic function.

17. The programmable logic block arrangement of claim 16, wherein each programmable logic element includes at least one storage element having an input port coupled to an output port of a corresponding lookup table.

18. The programmable logic block arrangement of claim 17, wherein each programmable logic element includes a programmable arithmetic circuit associated with a lookup table and having input ports and output ports, the input ports coupled to the output port of the associated lookup table and to an output port of an arithmetic circuit associated with another lookup table, the output ports coupled to an associated storage element and to an arithmetic circuit associated with another lookup table.

19. A programmable logic block arrangement, comprising:

a switch circuit;

a first set of programmable logic elements coupled to the switch circuit, wherein the programmable logic elements of the first set implement a first set of functions;

a second set of programmable logic elements coupled to the switch circuit, wherein the programmable logic elements of the second set implement a second set of functions that is a proper subset of the first set of functions, wherein a function in the first set and not in the second set is a distributed memory function, wherein selected bits of a distributed memory are stored in a programmable logic element.

20. The programmable logic block arrangement of claim 19, wherein a function in the first set and not in the second set is a shift register function.

21. The programmable logic block arrangement of claim 19, wherein each logic block includes an even number of programmable logic elements, one half of the programmable logic elements in each logic block are programmable to implement the first set of functions, and one half of the programmable logic elements in each logic block are programmable to implement the second set of functions.

22. The programmable logic block arrangement of claim 21, wherein each programmable logic element includes at least one lookup table having input ports coupled to the interconnect circuitry and programmable to implement a logic function.

23. The programmable logic block arrangement of claim 22, wherein each programmable logic element includes at least one storage element having an input port coupled to an output port of a corresponding lookup table and an output port coupled to the interconnect circuitry.

24. The programmable logic block arrangement of claim 23, wherein each programmable logic element includes a programmable arithmetic circuit associated with a lookup table and having input ports and output ports, the input ports coupled to the output port of the associated lookup table, the interconnect circuitry, and to an output port of an arithmetic circuit associated with another lookup table, the output ports coupled to an associated storage element, to the interconnect circuitry, and to an arithmetic circuit associated with another lookup table.