Programmable logic device with hierarchical confiquration and state storage

• US 5,778,439 A
• Filed: 08/18/1995
• Issued: 07/07/1998
• Est. Priority Date: 08/18/1995
• Status: Expired due to Term

• Current Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Original Assignee: Xilinx, Inc. (Advanced Micro Devices, Inc.)
• Inventors: Wong, Jennifer, Trimberger, Stephen M., Carberry, Richard A., Johnson, Robert Anders
• Primary Examiner(s): Swann, Tod R.
• Assistant Examiner(s): PEIKARI, BEHZAD
• Application Number:
  US08/517,019
• Time in Patent Office: 1,054 Days
• Field of Search: 395/483, 395/444, 395/445, 395/450, 395/497.04, 178/3, 364/DIG. 1, 364/497.01, 364/480
• US Class Current: 711/153
• CPC Class Codes: H03K 19/17748 Structural details of configuration resources
• CPC Class Codes: H03K 19/17752 for hot reconfiguration
• CPC Class Codes: H03K 19/17758 for speeding up configuration or reconfiguration
• CPC Class Codes: H03K 19/1776 for memories

Abstract

In accordance with the present invention, a programmable array includes hierarchical configuration and state storage. The array comprises an active storage for an active configuration and an active state as well as an inactive storage for one or more inactive configurations and one or more inactive states. The array further comprises logic and routing configured by the active configuration. The logic includes a plurality of combinational elements and a plurality of sequential logic elements for providing the states. Bits are transferred between the active and the inactive storage. The inactive storage is accessible for read or write operations by the active configuration by a structure comprising: a core including a plurality of configurable elements selectively coupled to each other, a memory controller for controlling the memory that configures the logic and routing in accordance with the active configuration, a command register to hold commands for the memory controller, a memory address register to address the memory, and a memory data register coupled to the memory and the plurality of combinational elements. In one embodiment, the array of the present invention includes a configurable routing structure for providing the active configuration access to the memory address register, the memory data register, and the command register. The configurable routing structure is generally controlled by signals from the user logic, thereby significantly increasing user flexibility in using the programmable array.

Claims

1. A programmable logic device with hierarchical configuration and state storage on an integrated chip, comprising:

an active storage for an active configuration and an active state;

an inactive storage for one or more inactive configurations and one or more inactive states;

logic and routing configured by the active configuration, wherein the logic includes a plurality of combinational elements and a plurality of sequential logic elements for providing the states; and

means to transfer the bits between active and inactive storage.

2. The programmable logic device of claim 1 wherein the inactive storage is divided between off-chip storage and on-chip storage.

3. The programmable logic device of claim 2 further including means to transfer the bits of said inactive storage between off-chip storage and on-chip storage.

4. The programmable logic device of claim 1 wherein said configurations and said states are stored separately.

5. The programmable logic device of claim 1 wherein said configurations and said states are stored together.

6. The programmable logic device of claim 1 wherein said inactive storage is provided off-chip.

7. The programmable logic device of claim 1 wherein the inactive storage is accessible for read or write operations by the active configuration by a structure comprising:

a core including a plurality of configurable elements selectively coupled to each other;

a memory controller for controlling the memory that configures the logic and routing in accordance with the active configuration;

a command register to hold commands for the memory controller, the command register operatively coupled to said logic, routing, and memory;

a memory address register to address the memory, the memory register operatively coupled to said logic, routing, and memory; and

a memory data register operatively coupled to said logic, routing, and memory.

8. The programmable logic device of claim 7 wherein the command register is located outside the core.

9. The programmable logic device of claim 7 wherein the memory controller is located outside the core.

10. The programmable logic device of claim 7 wherein the memory address register is located outside the core.

11. The programmable logic device of claim 7 wherein the memory data register is located outside the core.

12. The programmable logic device of claim 7 further including a configurable routing structure for providing the active configuration access to the memory address register, the memory data register, and the command register.

13. The programmable logic device of claim 12 wherein the configurable routing structure includes tristatable busses.

14. The programmable logic device of claim 12 wherein the configurable routing structure is controlled by signals from user logic.

15. The programmable logic device of claim 12 wherein transfers between the on-chip memory and the off-chip memory can be made by core logic and routing of the active configuration by:

a plurality of input/output elements coupled between the configurable routing structure and the off-chip memory.

16. The programmable logic device of claim 11 further including a plurality of dedicated logic paths for coupling the on-chip memory and the off-chip memory.

17. The programmable logic device of claim 7 further including a column data register and a path between the on-chip memory and the column data register with a width greater than the memory data register width.

18. The programmable logic device of claim 17 further including a path between the memory data register and the column data register, and a shifter to shift data between the smaller memory data register and any part of the larger column data register.

19. The programmable logic device of claim 18 further including means to access the column data register through the memory data register for multiple transfers associated with a single column data register to memory transfer.

20. The programmable logic device of claim 1 further including means for loading said inactive storage without interrupting said active storage.